Fallout 3 is freezing?

It does this anytime I walk through a door, rest, wait, or anything. I am in the Marketplace at Rivet City. It keeps doing this no matter what. I tried to turn it off and then back on. Letting it rest for a day or two. But it still does it!!! Idk what is wrong, Ive looked around and a few people have said to delete the cache of F3, but it never works. IDK what to do, I am at my wits end. PLEASE HELP!