Per $860 before rebate, that is a terrible build... No offense. At that cost, even before the $90 windows that's $770, you should be able to get a much better build.
Check out my $650 build here:
http://www.squidoo.com/electronicandmore#module146695821
Upgrade the FX-6300 to the FX-8320 (+$40)
http://www.newegg.com/Product/Product.aspx?Item=N82E16819113285
Upgrade the 7870 to the 7950 (+$70)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202006
Total: $730
You get a better CPU, it runs slightly more on the power consumption but at the end of the day on your power will only add like a few cents on your electric build. But you'll get a CPU that's great at multi-thread and normal applications, while retaining decent FPS numbers. Keep in mind in games like BF3, Metro 2033 or Crysis 2, all demanding games, the most crucial part to frames is not the CPU like most people think. It's the GPU. Sure you're not getting the i5 3450, but for $10 less, the FX-8320 can overclock, benchmarks better in most things while lacking a little in games. However, you're able to fit in a much better GPU.
Windows for cheap:
http://www.softwaresupplygroup.com/microsoft-windows-7-home-premium-64-bit-oem-branded.html
BBB A approved:
http://www.bbb.org/memphis/business-reviews/computer-software-publishers-and-developers/software-supply-group-in-cordova-tn-44050536
The total is less, you get a MUCH better GPU, better CPU and a better PSU.