Hi David..
everything has two sides..
a) you're probably right generally about the sledgeHammer
b) imho you're wrong in this here case..:
- even if PARITE is seemingly successfully removed/Cleaned, that doesn't mean that all programs will be successfully repaired/working..
(especially if avast & VRDB isn't working properly anymore).
And this sure can wreak havoc on your system ...
- OP had obviously some active trojans/worms probably with BackdoorFunctions -> the system's security is compromised already..
- For XP: There's SP2 available -> Just get the full Installer somehow on CD.
flatten your Windows-Partition, and reinstall (OFFLINE!!) XP + SP2, avast and maybe firewall..
Then you've a basic protection...
Secure Passwords, Secure Browser-settings of course still need to be done immediately...Plus SafeHex & Brain1.x