So, I just finished upgrading my computer. Before a few days ago, I had windows xp home 32-bit running 2 gb of RAM. I decided to upgrade and get windows 7 pro 64-bit. I knew I would need more memory, so I got myself a pair of 2 gb cards giving me a total of 6 gb. Prior to installing windows 7, i forgot to update my bios to support memory mapping. The installation went fine, but I noticed that I was able to use less than half my ram. If I update the bios now to enable memory mapping, and run off my hard drive, I get a BSOD. If I try to repair windows 7 by booting off the CD with memory mapping, it hangs after the "windows is loading files" screen. Everything is fine without memory mapping, except that I cant use all the memory. How can I get it fixed?