Is XP on a different logical drive? If so, it's pretty easy to lose it.
Right click on My Computer, select Properties, Advanced, Startup & Recovery.
Make sure the correct O/S is in the Window, and uncheck the "Time to display list of O/S" box.
Now, verify that you can boot cleanly directly into XP.
To clean out Win2K, you can remove the WINNT, Program Files, and Documents and Settings directory trees from C:, job done.
Right click on My Computer, select Properties, Advanced, Startup & Recovery.
Make sure the correct O/S is in the Window, and uncheck the "Time to display list of O/S" box.
Now, verify that you can boot cleanly directly into XP.
To clean out Win2K, you can remove the WINNT, Program Files, and Documents and Settings directory trees from C:, job done.