I have used XP professional for the last year with no issues other than having to disable my firewall, but there is a topic in the knowledge base that steps you through the process. Panelbuilder 1400e, Panelbuilder32, RSLogix,5, 500 and 5000 all run well.
The thing that gets to me the most is that the IT department specified the IBM R50 computer that I use and did not include a floppy drive or a serial port. I use an IBM USB floppy drive and a Cool Gear USBG-232-MM USB Serial Port with no issues.
Regards