have you tried doing the same from safe mode.
what program are you trying to uninstall. if it is a recent program that you installed and want to get rid of it you can try a system restore.

for a rapid response try emailing me at techsupport4free@gmail.com

Try running a system file check:
click start>run
type in: sfc /scannow
(space between sfc and /)
click OK

sfc will replace any damaged/missing system files. It may ask for your XP CD. When it's done, reboot and see if the problem is fixed.

Ron