where has that file gone?

Am still using my hard disk of 40 GB. A few days back I noted that my C drive is almost full. I never fill it above half or 3/4th. So I checked the installed s/w programs. I found a new s/w with 1 GB memory space. So, I could easily find out why my C drive was showing 'Memory full, delete a few files'. i uninstalled the program (Now I forgot its name :silly: :silly: :dry: ). But the operation failed and gave an error message. But when I checked in the installed program list that s/w was not there :whistle: ? If so, where has it gone? My C drive is almost full, just a few MB space left. I need to find that hidden thief from my folders. :P Is it possible? Otherwise formatting is the only solution to remove it.