Spontaneous Reboot After Virus

I'm having trouble with my HP Desktop running Windows XP Home. A virus brought my computer down a couple of days ago. The virus had the effect of redirecting me to commercial sites off of Google searches. This effect only seemed to be an issue with IE: Firefox didn't seem to be affected by it at all. After lots of scrubbing with a combo of anti-virus applications I was able to clear out my pc's infection. However, since then I've been experiencing intermittent reboots. Typically happens when I'm doing something memory intensive. It happened twice, for instance, when I was attempting to back up my hard disk. It's also knocked my active desktop out a few different times. I ran a scan on minidump files using WinDbg. Initially scans said problem with unknown driver. After adding diagnostic capacity to registry file however (altering registry so a specific error would print) and reexamining some of the earlier scans, I got an outcome of memory corruption.

I tried to beat this by altering virtual memory: thought virus may have impacted virtual memory somehow. Changed virtual memory to XP control and this seemed to have benefits for performance but I got another reboot when I tried another hard disk backup. I realize minidump readings for memory corruption can indicate RAM or other failure, but this was not an issue at all until the virus came and went. I can't believe it's simply coincidence that I'm experiencing this now. I never had reboots like this before.