Many XP users have been blaming Service Pack 3 for breaking remote desktop connections to their machines.  I, for one, have been unable to RDC into my Windows XP machine since the upgrade to Service Pack 3 as well.  However, the issue isn’t with Service Pack 3 at all! Nvidia is at fault!

I spent days (counted the hours) trying to figure out what changed in Service Pack 3 that would break Remote Desktop.  Visiting the Microsoft site and learning about the new security measures and how to enable the Credential Security Service Provider yielded no results.

In case you are interested:

• http://support.microsoft.com/kb/951616/en-us
• http://support.microsoft.com/kb/951608/

Oddly, around the same time I installed Service Pack 3 I also updated my nVidia drives to help me connect a Windows XP machine to a television in my office. This is where the problem comes from.  Unfortunately, I can’t tell you which versions of the driver the issues start with; I can tell you how to fix it.

NOTE: Editing the Registry incorrectly can cause serious, system-wide problems that may require you to re-install your operating system to correct them. Microsoft nor computingondemand.com cannot guarantee that any problems resulting from the use of Registry editing can be solved. Back up your registry first, but use at your own risk.

1. Start, Run, type regedit and press OK
2. Navigate to the Key: [HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerMemory Management]
3. Right click in the Details pane and Select New –> DWORD Value
4. Name it: SessionImageSize
5. After it is created, double click on it and change its value to: 20
6. Exit the Registry Editor and Reboot.

I also have a .reg file you can download: nvidiaregfix

As always, right click and verify its contents before importing into your Regsitry.

[HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerMemory Management]
“SessionImageSize”=dword:00000020