How much memory can your motherboard handle? I wouldn't recommend it with less than 4GB, especially if you're talking about a gaming rig.
And whether you mean that you have a quad or dual core (I don't quite understand) you're OK there.
You should also check out the manufacturer's website and see if they have Win7 x64 compatible drivers.
Yes 64bit windows 7 works without a problem. The motherboard itself only officially supports 2 gigs of ram though. Apparently there's some workarounds for it, but I never used them.
If your using an exotic GFX card like I was, 2600XT AGP, I'd strongly recommend downloading the appropriate drivers (or vista hotfix drivers in my case), prior to the installation.
The system itself doesn't feel sluggish at all on my dualcore firstname.lastname@example.org and boots a lot faster than XP ever did. By the way 2.5ghz was the highest stable overclock I could get on this ASrock board. Never bothered doing a BSEL mod since I just bought a new system altogether.
I now feel a little more relaxed, i did read somewhere that although the mobo only supports 2 g of ram you can get it to run 4g but I believe its something to do with the bios settings, and to tell you the truth thats now stepping out of my depth