I came across this topic when it was pointed out to me by Larry Franks, a colleague of mine from North Carolina.  As I look for topics to write about, I go through a variety of sources to see what people are having trouble with, and installation is by far the #1 issue.  To solve most installation problems, I highly recommend the Clean Machine approach, please refer to my previous post on this topic from April 1.  I cannot stress enough the importance of this, knowing what the environment on your machine is can also help in troubleshooting a failed install.  If you think that you can save time by installing on a machine that has had installs and uninstalls of other DBs, development environments, Operating Systems, etc., I can tell you that paving the machine and installing is much, much faster than troubleshooting a failed install on a machine that is a maze of old .dll’s, Frameworks, etc.  I know this from nearly 4 years on the phones at Microsoft as a Support Engineer – just setting up the test matrix t see what works and what does not is very time-consuming, and there is no guarantee that it can be fixed after all the troubleshooting steps.  The other factor to consider is how much you really want to trust a machine that has had an install “forced” on it.

In some cases, there may be no installation failure, you may just have a case where you need to install the latest bits all at once.  Starting with SQL Server 2008 SP1, this is now possible via a technique referred to as “Slipstreaming”.  In a nutshell, the idea is that you can copy the install files to your machine, then copy the SP1 files to your machine, then when Setup runs, it will install all the SP1 files instead of the “regular” ones.  As of now, this is not terribly important, but it certainly will be as the software matures, data centers phase out older versions, etc.

For the technical details on how this works, there is an excellent Knowledge Base article here:

 

http://support.microsoft.com/kb/955392