This usually means the SR data store is corrupted. The fix is to turn off
System Restore and turn it back on. This will remove all current restore
points but they are useless to you at the moment anyway. Open Control
Panel, open System, go to the System Restore tab, place a check next to
"Turn off System Restore on all drives." Click apply and ok and reboot the
system. Now, return to the same tab, remove the check, click apply and ok,
reboot. Then, manually create a restore point after which try to restore to
that point and see ...