I have just bought a new memory module and I was wondering what kind of settings (in virtual memory or elsewhere) should I make in order to improve performance. Could you guys help?

Basically, there’s nothing you can change that will really improve performance. Windows itself will just use the memory when it’s needed. Contrary to popular belief, Windows XP is pretty decent at using as much memory as you give it. You could change the memory usage to allocate more to the system cache but it’s only going to help you in specific circumstances.

What I really needed is that the common tasks were benefited from the RAM upgrade. A bigger system cahe would do that? If so, how do I change that?

Actually for common tasks it really won’t make a difference that you can tell. You can go into the System Control Panels and go to Performance and change the setting and restart your system.