I've just recently finished a build for a ~450$ budget gaming pc. Here are the specs: Pentium G630 2.7ghz 4GB DDR3 Sapphire 6870 1GB I run KSP at 1080p with 100+ parts with no hiccups. Unfortunetly, what a lot of people don't seem to realize when building a gaming pc, is that your Graphics Card is significantly more important than your processor (with some exceptions: KSP due to it's non-graphically intensive nature, Skyrim to an extent, GTA IV because it's terribly optimized, etc). And they'll go and drop 400$ on a processor and 150$ on a Graphics Card. A ~900$ general gaming pc would ideally include an i5, and something in the 7850-ish range. http://pcpartpicker.com/p/aPqa Here's a good 800$ build that I found. With windows 7, it'd bring the total up to around 930$. That Graphics card can max out pretty much any game at 1080p, and the processor will not bottleneck performance. It has both an SSD and an HDD (If you're not sure, the main difference is that anything on the SSD will load more quickly, be it games, an operating system, etc). There's also an aftermarket CPU cooler that will allow you to overclock if you see fit. If you plan to go with that build, or any other build that uses an aftermarket heat sink, here's a helpful video that showcases a great way to apply the thermal paste:
If this is the first time you're building a pc (assuming that you are going to be building it), I highly recommend that you use that channel to learn how to put everything together. They're really great at giving directions.
