wen i go in menu i press new game i get birth i had to wait 10 secs to pick my gender and my mom stops talking and everyone is standing still can you help me please? i tried reinstalling it

If it takes ten seconds to pick your gender, sounds like your cache might be clogged up. Clear that, and see if things load a little faster. Also, if this is a second or more playthrough, you might want to delete all but several saves, so the cache doesn't get so bloated.

i don't know how to delete it or know were it is i just got a save game and it works perfectly

I thought the PC version of Fallout 3 doesn't use a cache like the xbox 360 does. And seeing this is the PC issues forum I assume the OP is using a PC.

TheUnknown does your problem still persist. Seeing that you ended your last sentence with 'it works perfectly'?