XP can only use 2 gigs no matter how much is in the box, but it doesn't matter since I'm gonna need a new OS anyway.
Thank you that was very helpful. My computer is a very old (2008) Dell box, so I'm not going to use anything from the inside except the DVD drive. Plus I think the power switch on the case is broken and that's what's causing my trouble. What I think I'm going to do is scale back everything and forgo BluRay so I can get a new hard drive and a copy of Window 8.1. I'll just order it retail since getting one used sounds like it might be a hassle. I already have a couple hard drives, but one is very small and the other is an external USB drive. This build is based of the Good build rather than the Great build.
CPU Intel Core i5-4460 3.2GHz Quad-Core Processor
Motherboard Gigabyte GA-B85M-D3H Micro ATX LGA1150 Motherboard
Memory GeIL EVO Veloce Series 8GB (2 x 4GB) DDR3-1600 Memory
Storage Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive
Corsair 200R ATX Mid Tower Case
Power Supply EVGA 500W 80+ Bronze Certified ATX Power Supply
Operating System Microsoft Windows 8.1 (OEM) (64-bit)
http://pcpartpicker.com/p/bD3DhM
This comes to about $600 before shipping, so right at the top of what I want to spend. Does any one see any problems/have any suggestions about this? About what games would I be able to play if I added a decent graphics card to this?