I'm building a new system. Does sims 3 run on windows 7 and if so, should I base it on the recomended Vista Reqs?
More aboutsims system requirements windows
Yes, and yes.
If you want to run it on high settings , I'd say you need at least a HD 4650 (or a 9600GS), but a HD 4670 (or a 9600GT) would be best, combine that with at least 2GB RAM and and a dual core that's >2.2ghz and has at least 2mb cache.