ripped from other place...
Here is some kind of proof i guess... but not for XP SP2 RC1, just beta1 afaik.
concurrent is concurrent one or two boxes, no?
If you run XP SP2 beta 1, you can enable it now, the setting taken from Windows Server 2003 enables it for winXP sp2!
Limit though is you need to be logged on as different user.
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Contro l\Terminal Server\Licensing Core
Create a new DWORD entry "EnableConcurrentSessions" and assign a value of 1 to it. Concurrent Sessions is now enabled.
No need to reboot!