Hi all, thanks one more time for your extended support though time. Well, I found out the source of the problem- missing RAM. I have complained to the store where I have bought my PC, and they agreed to replace the missing RAM. My problem (I thought it would be fixed) persists. I have tried almost everything to solve it, but have found no solution so far. In Windows 7 64 bits, windows only shows 3.25GB usable in 4 GB total. I will post a screen (below) to help me solve it. Also, I have heard of an option in my BIOS called Memory Hole Remapping, but I am not sure if it affects all the RAM. Any help would be appreciated.
Screen: