ok 1st thing 1st
turn off system restore to rid your self of the virus there
right click "My Computer", click on system restore tab and tick the box that says"turn off system restore"
now that all the data has gone from system restore, uninstall and re-install Norton and update it
now do a virus scan and make sure all viruses have been cleaned and deleted
Next do a system file check
to do this go to start>run and type sfc /scannow (note the space between the sfc and /) remember to put your xp disc in