May 17, 2008 by alonb
If you have multiple users on your Windows XP machine, you might have heard it is possible to patch the terminal services service, to support multiple concurrent remote desktop connection (via RDP) to your computer.
Around the time Windows XP SP1 was released, a patched version of the file termsrv.dll could be found on the Internet, replacing this file with your existing one enabled the concurrent remote sessions support.
Yesterday I upgraded to Windows XP SP3 (you may ask if it isn’t too early? maybe so, but since I’ve already been using the latest RC for some time now, I felt confident enough to apply this update on my home computer). Anyhow, after updating to SP3, I discovered my computer no longer supports concurrent remote sessions.
Short Googling returned few articles explaining how to patch the termsrv.dll to support concurrent sessions, so I pulled out my favorite HEX editor and with few clicks everything was up and running again.
To save so time for other users (and myself when upgrading more computers), I’ve packaged the updated termsrv.dll file with another file that will make the required changes to your registry. (see the included readme.txt file for further instructions).
Download the patched version: termsrv_sp3_patch.rar
0. Go to C:\Windows\system32\dllcache and rename the termsrv.dll to termsrv.dll.bak
1. Go to \Windows\System32 folder and rename termsrv.dll to termsrv.dll.bak
2. Copy the new SP3 patched termsrv.dll to \Windows\System32 folder
3. Run the included registry patch “ts_concurrent_session_patch.reg” (by double clicking it), it will update the relevant registry values which are relevant to the concurrent sessions support.
3. Restart windows.
if you are currently using Terminal Services, you will need to start windows in safe mode before you can overwrite the existing termsrv.dll files.
I’ve added a note to the installation instructions suggesting to remove another copy of termsrv.dll that resides in the dllcache directory (Anthoney, thanks for the tip).
The previous download link died. I uploaded the file to a new location.