Just got Fallout 3 and it runs fine as far as graphics but would freeze up randomly ....
I saw a suggestion on a windows 7 forum to limit it to using only two cores..Seems to be working fine..is that the best fix?

That's part of the fix. You also need to have the game installed outside of your program files. Otherwise, the UAC will interfere with the game operation and any mod additions. If you have the default installation, uninstall the game and reinstall it in a location other than program files. During the install, a window will open asking if you want a defauld install or custom install, choose the custom install, than type in the path to your install location. For example: c:\. This will install the game on your hard drive and also create all necessary folders.

I downloaded using the latest version of impulse from game stop seems like there is no option to install on c:/drive?

According to this (but maybe its an older version) it can be set in your preferences
http://forums.stardock.com/344167

However , if the game is running pretty decent. Your install directory should be fine. Unless you start installing mods and experience problems do to the UAC.

If your just looking to enhance quality or tweak performance ... read through the tweak guide.
http://www.tweakguides.com/Fallout3_1.html

i registered after seeing this, no lie either, not bumping for no reason.

i have a quad core\win 7 like the op. i did the core fix at one point, i don't remember if i changed it later on or not. i might have if i was having issues or had to wipe my fallout 3 folder again due to mod issues, already had to do this 3 or so times. so older settings may have been wiped out. i haven't been troubleshooting fallout 3 for a long time now.

last graphics card put me through hell with nearly every game i own, got a new one, it's like night and day compared to the last one. basicly the card is not a problem. but after the first i had a paranoia of my steam games, dragon age was the first victim of this paranoia, i had to delete it to reduce my stress level. so i am desperate to get some help here. i've been doing this song and dance for several years now.

if the uac does crash the game at random, how do i fix it if i downloaded it through steam? it does everything on it's own, and it has specific files it uses. so how can i move it out of steam and expect it to run?

to be honest i've had steam installed in program files ever since i started using it, the only game i have a disk for that is on steam is portal 2, and i have more games then just portal and fallout. the valve games i have virtually no issues with, just the beth and bioware games. and i know you can't help me with dragon age.

but all my beth games are crash alcoholics, oblivion, skyrim, and fallout 3, but the worst one is fallout 3 as far as issues go.

also i have around 50 mods in fallout 3 and i run it windowed, it has multiple fix patches in it already. i have nearly gotten every issue in the book so far, but the only one i truly hate is the crash mouse lockdown, i named this one, i can't seem to find a bloody fix for it. basicly it crashes, windows does the crash popup thing, and no matter what i do i can't use the mouse or shut the game down, so i have to use the keyboard to ctrl alt delete and log out, reboot, or shut down the system. i can't even shut it down from task manager. and it is all because of that damn popup, so can i disable the popup, relocate the game, or shut down the uac to avoid this permently? whatever the fix is i will do it, i am losing my nerve over this issue. also i have the basic general fallout 3, trust me downloading all the dlc seperately was pain in the butt.

If its just you want it installed outside the UAC ... you can move your steam app outside of it.

Moving your Steam app directions can be found here >>> https://support.steampowered.com/kb_article.php?ref=7418-YUBN-8129

oh i didn't think it would work if i moved the folder, alot of programs are temperamental like that, thanks i didn't want to have to shut down the uac, i hate it but it does have security. but yeah i wanted to know if i could move it and everything would be fine.