The system files it says have the virus are c:/WINDOWS/system32/crashlog.tar.gz/crashlog.tar/Memory.dmp and c:/WINDOWS/system32/crashlog.tar.gz/crashlog.tar

Is this anything to do with System Restore by any chance? The only symptom I have at the moment is that when I turn off System Restore having run Avast and restart, the computer freezes when I try to turn it on again. I have to switch off the power (not the best way to restart your puter) and restart and then it lets me switch System Restore back on. As it’s in the crashlog memory file I’m wondering if it’s something to do with XP’s and Avast’s caching system.