Hello.
Please I Need Help GIGAYBTE Or Asus
for Game And Windows Vista TOP Performance
Games 40%
Windows Vista Performance 60%

It all depends on the boards you're looking for. And is stock performance your only metric, or are you interested in energy efficiency, overclockability, features, etc?

Edit: actually, it is only likely to make a couple of percent difference. Unless overclocking is a big thing, go with feature set and what you deem to be the best price and support.

Either company brand is fine. Both have there pros and cons.

Could you list your system build so far, and we can see what mobo would be better suited.

I trust Asus and when benched it is always one of the top
But stay away from nForce chipset