I was using my mother's computer tonight when suddenly this program System Tool Version 2.20 somehow took over. I rebooted and all the computer shows is warnings about infections and I can clear it up if buy the software. The computer was using Microsoft Security Essentials for protection, but it looks like this has completely trashed it. I tried deleting the program from the control menu, but it doesn't appear to have worked. How do I get rid of this thing? Will rebooting to an earlier version work? Also my own computer uses Norton and SpyDoctor for protection. Do they protect against this?