Lots of problems have all happened in the last two weeks. All my Firefox bookmarks disappeared, Home page is reset, System Resore turns itself off AVG runs unscheduled scan without icon being shown on the task bar. This has happened twice in the last 2 weeks.
My Yahoo email address was also inundated with spam, all 75K in size. No matter how many addresess I added to my spam blocker (110 at last count) they continued to pile up. I closed the account in the end.
I updated and ran CWShredder, AdAware, Spybot S&D and AVG. All ran from Safe Mode.
AVG was clean, S&D OK and Adaware showed 6 low level files which I fixed.