stephen mate, you dont need to wipe everything.
heres a link to my fix on beeping computer... follw the directions on there exactly (more or less)
http://www.bleepingcomputer.com/forums/topic73964.html
alternatively do the following:
1. turn off restore
2. run vondo fix
http://www.atribune.org/ccount/click.php?id=4
3. restart.
make sure your virus definitions are up to date.
this worked for me.
NAV has updated and now can handle vundo.