how do i cheak how much ram i am using because i need to know if i should get more or not. i cant really tell my from my pc because sometimes its ok and other times it just lags. anyone can help?
If you're running Windows 2000 or XP, you can press Ctrl + Alt + Delete and select 'Task Manager'. Once in Task Manager, click the Performance tab. This shows the amount of RAM installed, the amount of RAM in use, the peak amount of RAM used since you started the PC and also the amount of pagefile ("virtual memory") space that is being used. All of these are important factors when considering whether it's worth buying more RAM.
If you're running Windows 98 or ME, most of that information is available in different places - it's just not on one handy screen.