Hello. I'm using Windows 7 on one of my older boxes. It's an older AMD X2 and I just upgraded from 2GB to 4GB of PC3200 DDR. The issue is that Windows is not allowing all 4GB to be used. The system shows that 4GB is physically installed, but is only listing 3GB usable. This is somewhat interesting as there's nothing I've found so far that indicates why this would be happening. Granted, this is brand new memory (the 2GB I had and now 2GB new) so I haven't been able to validate if it's a memory issue; but I'm convinced it's a software issue because BIOS is showing 4GB installed and so is Win7. Here's a screenshot of systeminfo: Thanks in advance for all the help!