In case it requires a repeat:
I like being able to fix things remotely. If I have to go onsite and repair a computer.. well, I don’t like that. I’d much rather do everything remotely. One good thing about doing remote repairs is that the computer user doesn’t have to be around watching your every move. And with that you don’t have to interrupt their work either.

But then we get to RDP sessions – if a user is on an XP box and requires some help, there were two options:
1.) Kick the user off and RDP in as an administrator
2.) Share the user’s screen using a third party product (VNC/LogMeIn/GoToMyPC/PCAnywhere/TeamViewer/etc)

Both of those ways would not allow the end user to continue working. So neither is good when trying to troubleshoot a several hour problem.

So it got me to thinking – if there is a way to log in more than 3 times into a Windows Server with a hacked termserv.dll file, why isn’t it possible to do the same thing with XP?

Well it is.

***Attention***
Do this at your own risk. I did not edit this Microsoft DLL, so there may be some hidden underlying issues that come about after installing said file. I tested this on two systems – both of which are Windows XP Pro SP3 with a Volume License Key, fully up to date with patching, and both were brand new installs. Both systems were also on a domain (not a workgroup) with the most basic GPO’s applied. Microsoft does not condone hacking their DLLs, so using this file will probably void your support with them.

1.) Download the file Here, rename this file termsrv.dll
2.) Open My Computer, select Tools/Folder Options. Click on View. Now make sure Show hidden files and folders is selected.
3.) Navigate to C:\WINDOWS\system32\dllcache
4.) Copy termsrv.dll to this folder. If you already have a termsrv.dll here, rename this file termsrvOLD.dll. Then copy the new file to this directory.
5.) Back up a directory (C:\WINDOWS\system32) and rename termsrv.dll to termsrvOLD.dll. Now copy the new termsrv.dll to this directory.
6.) If the file is overwritten by Windows Protection, you will have to accomplish steps 3 through 5 in safe mode. Press F8 before Windows loads to select safe mode.
7.) Reboot your machine
8.) Download the batch file here. You can right-click and select Edit to see what this batch file does before running it.
9.) Run the batch file and now you should be able to connect from multiple computers!

For whatever reason, Windows XP seems to reset the necessary registry values whenever the computer reboots. If you want to make a startup script for your domain you can do so.

Make a batch file with the following:
reg import \\MYDOMAIN\SysVol\MYDOMAIN\installpackages\ts_concurrent_session_patch.reg
Then set this to run in the GPO for your machine(s) and user(s).