With XP and Windows Server 2003 having Remote Desktop functionality built-in it's become a standard way to maintain lab machines and to work remotely. I tend to use a combination of VNC for Windows 2000 and Remote Desktop (which I'll refer to as Terminal Services from now on) for W2K3 and 64-bit windows.
To support multiple sessions, applications running on terminal services clients need to specify Global namespaces when connecting to server objects (such as shared memory). When the APIs changed, a few fixes were required to Informix Dynamic Server to fully support terminal services.
Some people may run into problems using terminal services on XP as there are various trialware copies of IDS 9.40.TC2 for Windows floating about, including one downloadable from IIUG. The last terminal services bug was ironed out in IDS 7.31.TD9 and 9.40.TC5. (IDS 10 fully supports terminal services.)
For the completist, here are the bug fixes (with links to technotes where relevant):
151637 'ONSTAT -' IN 'TERMINAL SERVICES' SESSION REPORTS 'SHARED MEMORY NOT INITIALIZED ...' - fixed in 7.31.TD5 and 9.30.TC6 and higher
161355 SERVER INSTALL ON A FRESH XP MACHINE REPORTS THAT THE SERVER WAS NOT INITIALIZED CORRECTLY EVEN THOUGH THE SERVER INITIALIZED SUCCESSFULLY - fixed in 7.31.TD9 and 9.30.TC6 and higher
162925 SERVER INSTALLED ON .NET MACHINE REPORTS THAT THE SERVER WAS NOT INITIALIZED CORRECTLY EVEN THOUGH THE SERVER INITIALIZED SUCCESSFULLY - fixed in 7.31.TD9 and 9.40.TC4 and higher.
165897 ONBAR CAN FAIL WITH 'NO RESPONSE WAS RECEIVED FROM THE DATABASE SERVER' ON WINDOWS WITH TERMINAL SERVICES - fixed in 7.31.TD9 and 9.40.TC5 and higher.