one way to "purge" is to:
Start computer in "Safe Mode with command prompt"...this is done by pressing an F1-9 key(depending on your computer manufacture) when starting up.
Select Adminastrator
You should now be in the cmd.exe window
type "cd\"
type "del index.dat /s"
type "shutdown -r"
that should do it.
Cheers,
Williwaw