Hello there!

My name is Axel Rivera.  I am a Senior Support Escalation Engineer on the IE Support Team.  Of the past few weeks, many of my customers have come across this issue and so I thought this would be a blog that you might find worth while.

When starting the Remote Desktop Web Connection window after installing Windows XP Service Pack 3, the following error may occur:

Remote Desktop Web Connection ActiveX control could not be installed. A connection cannot be made without a working installed version of the control. Please contact the server administrator.

Note:  The Connect button remains grayed out, as well.

This behavior is due to the Microsoft RDP ActiveX Control being disabled installing Windows XP Service Pack 3 or Windows Small Business Server 2003 SP1 on your machine. 

It’s important to note that you may see other symptoms, as well.  These symptoms include:

If the user tries to enable the ActiveX control using the Manage add-ons dialog in Internet Explorer, the Microsoft RDP Active control may not be listed.

This can happen if a machine is built from an OS image with Service Pack 3 for Windows XP slipstreamed.  Windows XP machines that were upgraded to XP SP3 will likely not have this problem and can enable the control using the process documented in KB Article located here.

To get this working again, please use one of the following methods to enable the ActiveX control:

Method 1 
Use the Manage Add-ons dialog in Internet Explorer to enable the Terminal Services ActiveX Control.  See KB951607 for further instruction.

If the ActiveX control is not listed in Manage Add-ons dialog, follow Method 2 below.

Method 2
1. Click Start, Run. Type Regedit.exe and press ENTER

2. Navigate to the following branch:
    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Ext\Settings

3. Double-click Settings to expand the branch.

4. Right-click {7584c670-2274-4efb-b00b-d6aaba6d3850} and choose Delete 
    (Repeat step 4 to delete any other problem keys)

5. Click Yes when asked for confirmation.
    Close all instances of Internet Explorer and re-run Remote Desktop Web Connection.

Registry Solution

Enable the below class ID:

Windows Registry Editor Version 5.00

[-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Ext\Settings\{7584c670-2274-4efb-b00b-d6aaba6d3850}]

Disable the below class ID:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Ext\Settings\{7584c670-2274-4efb-b00b-d6aaba6d3850}]
"Flags"=dword:00000001
"Version"="*"

Example of all the registry keys that you may need to delete to make it all work:

Windows Registry Editor Version 5.00

[-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Ext\Settings\{7584c670-2274-4efb-b00b-d6aaba6d3850}]
[-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Ext\Settings\{4eb89ff4-7f78-4a0f-8b8d-2bf02e94e4b2}]
[-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Ext\Settings\{7390f3d8-0439-4c05-91e3-cf5cb290c3d0}]

Note: You may also need to completely remove the below registry keys

More Information:

If the Windows XP/SP3 service pack is download and then extracted, you can find a VBS script that can be used to rectify the problem.

The file name is: tscuinst.vbs

Command: cmd.exe /C "cscript %systemroot%\Installer\TSClientMsiTrans\tscuinst.vbs"

Regards,

The IE Support Team