*** NOTE: You can avoid having to make any ugly hacks to your PC by simply upgrading to XP SP3 final. Get the download of the SP3 from the download page.

So after much dismay regarding Microsoft’s “lack” of support for WebApp on the xP OS, I set out on a quest to obtain as much information as possible on this solutions. After hearing about some people’s success in getting the RDP bits from XP SP3 RC2 to work, I upgraded my PC to this release and it STILL DID NOT WORK!

Finally I located a RAR file from http://www.terminalserviceslog.com/ with the mystery files enclosed – these seemed to do the trick ONLY ONCE I copied the entire contents to the C:\Windows\System32 folder then ran regsvr32 c:\windows\system32\mstscax.dll (this is the NEW Terminal Services ActiveX control for web-based access) from the command prompt.

Since I have many dreams of using WebApp for my medical clients (since their current Citrix hosting provider is 18 month out with no resolution to the slowness for their hosted application), I needed a way to quickly deploy RDP 6.1 support in an xP environment.

Here is my process:

• Install RDP 6.0 from Microsoft. If you have everything closed you can typically avoid a reboot 🙂
• Update the RDP install to 6.1

I’ve created a nifty ZIP package that will take the guesswork out of the process. Download here

Upon running update.bat (included in the download above) this package:

• Copies the necessary RDP 6.1 support files to the C:\Windows\System folder.
• Copies mstsc.exe and mstscax.dll to the necessary Windows folders to prevent the original files from mysteriously creeping back onto your system. You can take Windows File Protection for this.
• Registers the mstscax.dll – THIS IS KEY TO THE WHOLE PROCESS!

Once I launched into my WebApp portal, I had to allow the ActiveX control to run (or alternately, add the URL to my Trusted Sites). This did the trick, and I was able to load up the WebApp portal plus connect to any of the “published” applications on any xP platform.

Special thanks to Richard Gard for the recommended changes to avoid Windows File Protection reverting these changes.