Can't access user profiles

Hello,My computer uses Windows XP service pack 3 as its
operational system. I recently uninstalled McAffe antivirus. Afterward I
did a reboot and everything seemed a usual until the light blue screen
appeared. It took over five minutes for the system to load the user
profiles. When I selected a profile I again waited a couple of minutes,
until the background image for the specific profile (but nothing else)
appeared. Finally I waited for a quarter of an hour only to witness the
computer doing a reboot by itself.

I can't access the computer at
all, not even in Safe mode but that is merely because I never get the
chance to press F8. After the, I believe it's called, CMOS ROM screen
disappears the Windows loading screen appears directly. This has always
been the case.

Thanks in advanceSebastian