It already is zero,so i would leave it.
NOTE:be very careful with the registry.if you delete something there could be serious issues.
If at sometime you have to edit an entry always backup first.
HOW TO EXPORT:open reg edit>high lite the entry in question (left pane)>on top click on registry>export file registry>you are given an option as to where to save it.
Did you try what 19sd78 suggested in the previous post.
Also heres another LINK
Don't forget to scan.