If you use Windows XP pro you will need to disable simple file sharing.
Open My Computer and go to Tools, Folder Options, View, and uncheck the
last entry simple file sharing.
You can delete the Restore points but you should be confident when
the virus infected the system and then delete all the restore points
after that date.
It's located in the c:\System Volume Information\_restore{41D13
folder. You will need to right click on this folder and add your account
to the Security Tab, then once you delete the restore points, remove
your account from the Security Tab.
Worked4me