Engineering Windows 7

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User Account Control

User Account Control

We promised that this blog would provide a view of Engineering Windows 7 and that means that we would cover the full range of topics—from performance to user interface, technical and non-technical topics, and of course easy topics and controversial topics.  This post is about User Account Control.  Our author is Ben Fathi, vice president for core OS development.  UAC is a feature that crosses many aspects of the Windows architecture—security, accounts, user interface, design, and so on—we had several other members of the team contribute to the post. 

We continue to value the discussion that the posts seem to inspire—we are betting (not literally of course) that this post will bring out comments from even the most reserved of our readers.  Let’s keep the comments constructive and on-topic for this one.

FWIW, the server employs some throttles on comments that aim to reduce spam.  We don’t control this and have all the “unmoderated” options checked.  I can’t publish the spam protection rules since that sort of defeats the purpose (and I don’t know them).  However, I apologize if your comment doesn’t make it through.  --Steven

User Account Control (UAC) is, arguably, one of the most controversial features in Windows Vista. Why did Microsoft add all those popups to Windows? Does it actually improve security? Doesn’t everyone just click “continue”? Has anyone in Redmond heard the feedback on users and reviewers? Has anyone seen a tv commercial about this feature? 

In the course of working on Windows 7 we have taken a hard look at UAC – examining customer feedback, volumes of data, the software ecosystem, and Windows itself. Let’s start by looking at why UAC came to be and our approach in Vista.

The Why of UAC

Technical details aside, UAC is really about informing you before any “system-level” change is made to your computer, thus enabling you to be in control of your system. An “unwanted change” can be malicious, such as a virus turning off the firewall or a rootkit stealthily taking over the machine. However an “unwanted change” can also be actions from people who have limited privileges, such as a child trying to bypass Parental Controls on the family computer or an employee installing prohibited software on a work computer. Windows NT has always supported multiple user account types – one of which is the “standard user,” which does not have the administrative privileges necessary to make changes like these. Enterprises can (and commonly do) supply most employees with a standard user account while providing a few IT pros administrative privileges. A standard user can’t make system level changes, even accidentally, by going to a malicious website or installing the wrong program. Controlling the changes most people can make to the computer reduces help desk calls and the overall Total Cost of Ownership (TCO) to the company. At home, a parent can create a standard user account for the children and use Parental Controls to protect them.

However, outside the enterprise and the Parental Controls case, most machines (75%) have a single account with full admin privileges. This is partly due to the first user account defaulting to administrator, since an administrator on the machine is required, and partly due to the fact that people want and expect to be in control of their computer. Since most users have an Administrator account, this has historically created an environment where most applications, as well as some Windows components, always assumed they could make system-level changes to the system. Software written this way would not work for standard users, such as the enterprise user and parental control cases mentioned above. Additionally, giving every application full access to the computer left the door open for damaging changes to the system, either intentionally (by malware) or unintentionally (by poorly written software.)

Percentage of machines (server excluded) with one or more user accounts from January 2008 to June 2008.  75% of machines have one account.

Figure 1. Percentage of machines (server excluded) with one or more user accounts from January 2008 to June 2008.

User Account Control was implemented in Vista to address two key issues: one, incompatibility of software across user types and two, the lack of user knowledge of system-level changes. We expanded the account types by adding the Protected Admin (PA), which became the default type for the first account on the system. When a PA user logs into the system, she is given two security tokens – one identical to the Standard User token that is sufficient for most basic privileges and a second with full Administrator privileges. Standard users receive only the basic token, but can bring in an Administrator token from another account if needed.

When the system detects that the user wants to perform an operation which requires administrative privileges, the display is switched to “secure desktop” mode, and the user is presented with a prompt asking for approval. The reason the display is transitioned to “secure desktop” is to avoid malicious software attacks that attempt to get you to click yes to the UAC prompt by mimicking the UAC interface (spoofing the UI.) They are not able to do this when the desktop is in its “secure” state. Protected Admin users are thus informed of any system changes, and only need to click yes to approve the action. A standard user sees a similar dialog, but one that enables her to enter Administrative credentials (via password, smart card PIN, fingerprint, etc) from another account to bring in the Administrator privileges needed to complete the action. In the case of a home system utilizing Parental Controls, the parent would enter his or her login name and password to install the software, thus enabling the parent to be in control of software added to the system or changes made to the system. In the enterprise case, the IT administrator can control the prompts through group policy such that the standard user just gets a message informing her that she cannot change system state.

What we have learned so far

We are always trying to improve Windows, especially in the areas that affect our customers the most. This section will look at the data around the ecosystem, Windows, and end-users—recognizing that the data itself does not tell the story of annoyance or frustration that many reading this post might feel. 

UAC has had a significant impact on the software ecosystem, Vista users, and Windows itself. As mentioned in previous posts, there are ways for our customers to voluntarily and anonymously send us data on how they use our features (Customer Experience Improvement Program, Windows Feedback Panel, user surveys, user in field testing, blog posts, and in house usability testing). The data and feedback we collect help inform and prioritize the decisions we make about our feature designs. From this data, we’ve learned a lot about UAC’s impact.

Impact on the software ecosystem

UAC has resulted in a radical reduction in the number of applications that unnecessarily require admin privileges, which is something we think improves the overall quality of software and reduces the risks inherent in software on a machine which requires full administrative access to the system.

In the first several months after Vista was available for use, people were experiencing a UAC prompt in 50% of their “sessions” - a session is everything that happens from logon to logoff or within 24 hours. Furthermore, there were 775,312 unique applications (note: this shows the volume of unique software that Windows supports!) producing prompts (note that installers and the application itself are not counted as the same program.) This seems large, and it is since much of the software ecosystem unnecessarily required admin privileges to run. As the ecosystem has updated their software, far fewer applications are requiring admin privileges. Customer Experience Improvement Program data from August 2008 indicates the number of applications and tasks generating a prompt has declined from 775,312 to 168,149.

Number of unique applications and tasks creating UAC prompts.  Shows a significant decline.

Figure 2. Number of unique applications and tasks creating UAC prompts.

This reduction means more programs work well for Standard Users without prompting every time they run or accidentally changing an administrative or system setting. In addition, we also expect that as people use their machines longer they are installing new software or configuring Windows settings less frequently, which results in fewer prompts, or conversely when a machine is new that is when there is unusually high activity with respect to administrative needs. Customer Experience Improvement Program data indicates that the number of sessions with one or more UAC prompts has declined from 50% to 33% of sessions with Vista SP1.

Percentage of sessions with prompts over time. 

Figure 3. Percentage of sessions with prompts over time.

Impact on Windows

An immediate result of UAC was the increase in engineering quality of Windows. There are now far fewer Windows components with full access to the system. Additionally, all the components that still need to access the full system must ask the user for permission to do so. We know from our data that Windows itself accounts for about 40% of all UAC prompts. This is even more dramatic when you look at the most frequent prompts: Windows components accounted for 17 of the top 50 UAC prompts in Vista and 29 of the top 50 in Vista SP1. Some targeted improvements in Vista SP1 reduced Windows prompts from frequently used components such as the copy engine, but clearly we have more we can (and will) do. The ecosystem also worked hard to reduce their prompts, thus the number of Windows components on the top 50 list increased. Windows has more of an opportunity to make deeper architectural changes in Windows 7, so you can expect fewer prompts from Windows components. Reducing prompts in the software ecosystem and in Windows is a win-win proposition. It enables people to feel confident they have a greater choice of software that does not make potentially destabilizing changes to the system, and it enables people to more readily identify critical prompts, thus providing a more confident sense of control.

One important area of feedback we’ve heard a lot about is the number of prompts encountered during a download from Internet Explorer. This is a specific example of a more common situation - where an application’s security dialogs overlap with User Account Control. Since XP Service Pack 2, IE has used a security dialog to warn users before running programs from the internet. In Vista, this often results in a double prompt – IE’s security dialog, followed immediately by a UAC dialog. This is an area that should be properly addressed.

Number of Microsoft prompters in the top 50 over time.

Figure 4. Number of Microsoft prompters in the top 50 over time.

Impact on Customers

One extra click to do normal things like open the device manager, install software, or turn off your firewall is sometimes confusing and frustrating for our users. Here is a representative sample of the feedback we’ve received from the Windows Feedback Panel:

  • “I do not like to be continuously asked if I want to do what I just told the computer to do.”
  • “I feel like I am asked by Vista to approve every little thing that I do on my PC and I find it very aggravating.”
  • “The constant asking for input to make any changes is annoying. But it is good that it makes kids ask me for password for stuff they are trying to change.”
  • “Please work on simplifying the User Account control.....highly perplexing and bothersome at times”

We understand adding an extra click can be annoying, especially for users who are highly knowledgeable about what is happening with their system (or for people just trying to get work done). However, for most users, the potential benefit is that UAC forces malware or poorly written software to show itself and get your approval before it can potentially harm the system.

Does this make the system more secure? If every user of Windows were an expert that understands the cause/effect of all operations, the UAC prompt would make perfect sense and nothing malicious would slip through. The reality is that some people don’t read the prompts, and thus gain no benefit from them (and are just annoyed). In Vista, some power users have chosen to disable UAC – a setting that is admittedly hard to find. We don’t recommend you do this, but we understand you find value in the ability to turn UAC off. For the rest of you who try to figure out what is going on by reading the UAC prompt , there is the potential for a definite security benefit if you take the time to analyze each prompt and decide if it’s something you want to happen. However, we haven’t made things easy on you - the dialogs in Vista aren’t easy to decipher and are often not memorable. In one lab study we conducted, only 13% of participants could provide specific details about why they were seeing a UAC dialog in Vista.  Some didn’t remember they had seen a dialog at all when asked about it. Additionally, we are seeing consumer administrators approving 89% of prompts in Vista and 91% in SP1. We are obviously concerned users are responding out of habit due to the large number of prompts rather than focusing on the critical prompts and making confident decisions. Many would say this is entirely predictable.

Percentage of prompts over time per prompt type.

Figure 5. Percentage of prompts over time per prompt type.

Percentage of UAC prompts allowed over time.

Figure 6. Percentage of UAC prompts allowed over time.

Looking ahead…

Now that we have the data and feedback, we can look ahead at how UAC will evolve—we continue to feel the goal we have for UAC is a good one and so it is our job to find a solution that does not abandon this goal. UAC was created with the intention of putting you in control of your system, reducing cost of ownership over time, and improving the software ecosystem. What we’ve learned is that we only got part of the way there in Vista and some folks think we accomplished the opposite.

Based on what we’ve learned from our data and feedback we need to address several key issues in Windows 7:

  • Reduce unnecessary or duplicated prompts in Windows and the ecosystem, such that critical prompts can be more easily identified.
  • Enable our customers to be more confident that they are in control of their systems.
  • Make prompts informative such that people can make more confident choices.
  • Provide better and more obvious control over the mechanism.

The benefits UAC has provided to the ecosystem and Windows are clear; we need to continue that work. By successfully enabling standard users UAC has achieved its goal of giving IT administrators and parents greater control to lock down their systems for certain users. As shown in our data above, we’ve seen the number of external applications and Windows components that unnecessarily require Admin privileges dramatically drop. This also has the direct benefit of reducing the total amount of prompts users see, a common complaint we hear frequently. Moving forward we will look at the scenarios we think are most important for our users so we can ensure none of these scenarios include prompts that can be avoided. Additionally, we will look at “top prompters” and continue to engage with third-party software vendors and internal Microsoft teams to further reduce unnecessary prompts.

More importantly, as we evolve UAC for Windows 7 we will address the customer feedback and satisfaction issues with the prompts themselves. We’ve heard loud and clear that you are frustrated. You find the prompts too frequent, annoying, and confusing. We still want to provide you control over what changes can happen to your system, but we want to provide you a better overall experience. We believe this can be achieved by focusing on two key principles. 1) Broaden the control you have over the UAC notifications. We will continue to give you control over the changes made to your system, but in Windows 7, we will also provide options such that when you use the system as an administrator you can determine the range of notifications that you receive. 2) Provide additional and more relevant information in the user interface. We will improve the dialog UI so that you can better understand and make more informed choices. We’ve already run new design concepts based on this principle through our in-house usability testing and we’ve seen very positive results. 83% of participants could provide specific details about why they were seeing the dialog. Participants preferred the new concepts because they are “simple”, “highlight verified publishers,” “provide the file origin,” and “ask a meaningful question.” 

In summary, yes, we’ve heard the responses to the UAC feature – both positive and negative. We plan to continue to build on the benefits UAC provides as an agent for standard user, making systems more secure. In doing so, we will also address the overwhelming feedback that the user experience must improve.

Ben Fathi

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  • Please add 5 and 2 and type the answer here:
  • Post
  • Regarding the post from ababiec:

    > If we can't shut off UAC for external drives,

    > then at least give me the option to enter

    > "Admin" mode for the entire session while I am

    > doing file mgmt. I can't find a way to run

    > Windows Explorer as an Administrator.

    Open a command prompt using "Run as Administrator" (i.e. right click on cmd.exe and then Run As Administrator).  In the resultant elevated command prompt, type "explorer /separate".  The resultant explorer window (and  only this window) will have a full admin token - and, therefore, will not trigger any UAC prompts.

    If you require another elevated instance, you can "explorer /separate" again from the elavated cmd.exe prompt.  To differentiate between filtered and full instances of explorer.exe, I recommend the use of PrivBar.



  • UAC is a malicious program.

    I kill it on first sight ever since I got Vista.

    Then I kill security center alerts, to get rid of "UAC not working" messages.

    This way I went on with Vista and didn't go back to XP.

    It is most important for me to be able to kill both alerts and virtualization of UAC.

    Otherwise I won't follow with Seven.

    Build a user mode by default during installation.

    And make it work right.

  • A few folks have suggested we create 2 accounts, one admin and one standard user.  This is definitely something worth considering of course.

    There are two things we keep having to consider:

    * A most common support call to OEMs and Microsoft is "lost password".  This would effectively double the chances of a lost password.  Also, by having the "Administrator" named account on the machine creates an obvious entry point for dictionary attacks.  

    * The out of box experience (that is the time from opening the box to getting on the internet) is a big design point--creating two user name/password combinations seems counter to that goal as well. Asking for two unique user names at the start seems awkward in terms of what most folks would believe to be required.

    Just something that we're thinking about...


  • Whats the idea behind that "to change the User Account Control message behavior" I have to have Windows Vista Enterprise or Windows Vista Ultimate?

    Home versions does not need proper UAC?

    I still can not see the advantage of UAC as implemented now. MS educated the user to click "Yes" every popup he sees.

    Exactly how is UAC makes the system safer? Are there significant user group who actually reads them?

  • Like someone else said on here, I'm getting more worried about this blog as time goes by. MS has hinted that they'll release an alpha fairly soon, possibly in a few months, and a release within a year. We can't still be discussing basic concepts such as these and meet that timeline. I think the feature set has already been decided, and we're simply being softened up for what is already coming. And most of that is simply a warming over of concepts that already exist in Vista, such as UAC, which just don't work and can't ever work because they come at an issue from the wrong angle. I really am getting the feeling that MS believe Vista can simply be tweaked. We've seen discussions on the basic fundamental OS building blocks, that basically haven't gone anywhere: they see no problem with what they have or are 'locked into' some concepts that are fundamentally flawed. I'm seeing the same here. There's analysis galore, but it all makes the same fundamental mistake: its looking to fix or tweak something that shouldn't be the starting point in the first place. MS need to go back and look at the iPod and Wii: they changed the game with their UIs and avoided the problems of existing UIs and interaction by simply doing it differently at the outset.

  • Other than the frequency of the prompts, the two most annoying this about it are the

        -delay, which leaves installer at 0% for some time before UAC pops up.

        -the fact that it locks up the whole screen (although it does go int the background sometimes.

    A better way would be to instead pop-up a little message on the side above the system tray (similar to live messenger), and have it stay there, which would probably reduce all the funny graphics stuff that happens.

    And I agree that there really should be a safe list that frequent programs could be added to.

    In addition to this though, Windows really should have some of the common programs, like security suites, already recognized, much like firewalls in recent days have become smarter and instead of prompting users, they make smart decisions, which for the most are 'smart'.

  • Well to the above commentator, I too agree that Win7 must be under feature lockdown with Beta 1's supposed release this December.

    Though, the posts on this blog are still useful as the team has time to 'fine-tune' existing components of the OS, which is exactly what they are trying to do.

    Im sure MS and the windows team within the company know that a lot is riding on this release being successful and to eradicate the misconceptions people have of Vista as we no way can have a repeat of that episode.

  • I have been following these comments and I agree with many.

    UAC does seem to slow down productivity because of the "lag" it causes before and after it asks for permission.

    Security center really needs to "forget" about UAC. It never seems to give up on it (create an option for this please!).

    It would be great to for us interesting in the engineering of W7 to understand how our comments/posts help improve/shape W7 when we are so close to beta 1 and I (as others) guess that now W7 is feature locked?

    I would also greatly appreciate if staff replies in the comments area where shaded another colour so I can identify who is staff and who isn't.

  • How often do I change my mouse settings? Irrelevant! What's relevant is that someone decided changing mouse settings was a potentially dangerous act that needed to be UAC'd. Utterly moronic thinking.

    Manic marc:

    Linux and Mac users are welcome to laugh in someone's face if they suggest anti-virus, but the idea that they are inherently "secure" is not at all true, as was proved with the Month of Apple Bugs.

    A recent Apple critical security update was 300megs - for 3 apps. That's as big as service pack 3, which contains every critical patch ever released for XP. BSD was recently exposed as having a critical security flaw that was in place since... the BSD project started, over 20 years ago.

    The only reason macs and linux don't have AV is that malicious hackers haven't started targetting them yet. If they start, you can expect to see a lot of people with their smug pants around their ankles very quickly indeed.

  • You know those movies... where someone is being guarded by someone for some reason (Politicians wife/kid, witness in a murder trial, etc..), and they get frustrated by all the security, and find a way to escape by themselves?

    Invariably, the person gets themselves into trouble they can't handle.

    That's what most of the people complaining about UAC are like.  They whine and moan about how bad UAC is, but as soon as they ditch it, they get themslves in trouble.

  • I would like to see a way to adjust the UAC to different threat levels like how IE has different levels of security.  UAC should have a Low, Medium, High and Custom.  This would cater to everyone if they made it easy to do so.

  • Given all your research data, I wonder if you ever found a survey that provides you with an answer to: Given a 'proceed' or 'do nothing' choice, what would an ordinary person do? Factoring in also that there may be 'warnings' of mild or dire consequences to their actions.

    I for one would do nothing.  I don't want anything happening.  Therefore I am unable to operate your software products, as 'doing nothing' turns the computer into a dead machine.

    So, make sure you have a 'kill the little stinker' built into Windows 7, as I like computing!  :-)

  • Steven Sinofsky wrote "A few folks have suggested we create 2 accounts, one admin and one standard user.  This is definitely something worth considering of course. ...etc"

    I'm against that too in regard to the typical home users.

    We can do everything through the UAC, we don't need a second account. Maybe a switch to an "administrator mode" to temporarily lift restrictions could be appropriate in some cases, when needed.


    "A most common support call to OEMs and Microsoft is "lost password".

    For many home users a password is useless. It should be clearly optionable. You can leave the box blank, but poeple feel obliged to type in something, preferably difficult to remember. Replace the box by a button reading [password...], under "advanced options" and lost passwords will be a thing of the past.

    It's also important that noobs know that you can always change the statu and password and everything on the account later when necessary.

  • I have no problem with UAC. I'm glad though you are making a UAC control center to control the prompts. If only you did this sooner.

    Looking forward to seeing this in person

  • One thing that I really hate about UAC is it blocks everything on screen when displaying it's dialog box, that's the reason it's very annoying. And the UAC dialog box should also display if the executable is signed or not and the digital signature is valid or not. Actually Windows 7 should do this before launching any applications besides the installed ones.

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