system freeze or lock

[Carlos]

Hello,
My problem is that my system freezes or locks up on me.
Prior to the virus that I got i had no problems with my
system. I removed the virus and that is when the problem
started. I since then have done 3 clean installs and
formatted to ntfs file system with windows xp pro. I have
updated all software and drivers for xp. The system locks
up randomly and not very often but it is very bothersome.
All I can do is press the reboot button. Can anyone
please help me with this problem.

Thanks
Carlos