Assuming you really have a virus
If you have all your photos and personal information backed up, then use your windows disk to format your hard disk and re-install windows.
If you don't have a backup, buy a new cheap HDD, install windows on that with your other drive unplugged,
switch off, then reconnect it so you have 2 HDD
boot your computer using the new windows installation
copy all jpg and docs and emails from old hdd to new one. Don't copy any programs.
Format your old hdd.