System Restore = Unwanted Files?

Ok new comp. problem.

SO with this new computer I have - I screwed up some installations and went back to default settings via System Restore (which I’ll turn off as soon as I get my comp where I want it)…problem is - that now my hard drive says I have space used up that shouldn’t be there because if we are to think of this literally - then whatever was there before - should be gone now. etc. etc. etc.

Is there a program out there that can find these files (because I can’t find them in the actual programs folder taking up space etc.) and use it to delete these unwanted files?

Any help is as always appreciated.

Thanks in advance.