Registry Deletions

Vista o/s with IE9. In general, this is a slow computer which is about 6 to 7 yeas old. I have read about and heard about numerous references being made to "leftovers" in the Registry. Accessing the registry and aiming only at the software of each of the items, I can see hundreds of entries pertaining to things that are long gone from the computer. i.e WorksShoebox.Shebox Catague which I understand educational institutions use for keep track of students progress. That fits, since our grandson was taking some college courses and spent a lot of time on that computer. I guess basically, my question is if those things were removed, will it help the performance of the computer. There are a lot of pros and cons about making adjustments to the Registry. Can I get some input? Thank You.

 

Run CCleaner on the registry, that should clear up a lot of stuff.

Anyway, if there's a ton of stuff in there, get rid of the keys. However look in the Program Files folders because most software is too lazy to uninstall itself properly...