ALL THOSE `CCOKIES'and not a one to eat

I deleted 3,062 out of temporary files today and this is after I removed Gator. Daughter's computer has Gator and very few cookies.She DOESN'T have iWON PrizeMachine and I did until I found out It was a form of spyware.Can anyone enlighten me and how much of this is safe to remove?

I had accumulated so many cookies that I felt they were some how muking up my pc. Now understand I am NOT very computer saavy!!! So, being the "whatever you read in the techie books and follow the instructions" kind of person I proceeded. I did this on a sunday night -cleaned cookies,video, audio and download file. Also defraged and dumped the recycle bin. Mon morningy my pc was dead. Now, I am not saying these things don't need to be done but don't be like me and start deleting everyting YOU think is not useful. The end result was I lost all my data and had to completely reinstall windows and any peripheral programs. It was a MESS! Cleanup is good but too much can cause problems...
Maybe someone else here has some good advice about computer cleanup and maintenance:
kt