When you're running Windows on a system with 4GB RAM, you might have noticed that the entire amount of RAM is not detected (it's somewhere around 3.6GB). This is because of the way HIGHMEM (4GB and up) is handled.
Fortunately, there is a way to solve the problem, allowing the full use of 4GB...
A solution to our problem is by forcibly enabling Intel's Physical Address Extension (in short, PAE). This is done by taking the following steps:
This little trick works with Windows 2000 Server family (with SP4), and Windows 2003.