If your system responds slowly or accesses the hard drive constantly, then you need to add more RAM. If you are running Windows 95/98, you need a bare minimum of 32 MB, and your computer will work much better with 64 MB. Windows NT/2000 needs at least 64 MB, and it will take everything you can throw at it, so you'll probably want 128 MB or more.

Linux works happily on a system with only 4 MB of RAM. If you plan to add X-Windows or do much serious work, however, you'll probably want 64 MB. Apple Mac OS systems will work with 16 MB, but you should probably have a minimum of 32 MB.

The amount of RAM listed for each system above is estimated for normal usage -- accessing the Internet, word processing, standard home/office applications and light entertainment. If you do computer-aided design (CAD), 3-D modeling/animation or heavy data processing, or if you are a serious gamer, then you will most likely need more RAM. You may also need more RAM if your computer acts as a server of some sort ( Web pages , database, application, FTP or network ).

Another question is how much VRAM you want on your video card. Almost all cards that you can buy today have at least 8 MB of RAM. This is normally enough to operate in a typical office environment. You should probably invest in a 32-MB graphics card if you want to do any of the following:

• Play realistic games
• Capture and edit video
• Create 3-D graphics
• Work in a high-resolution, full-color environment
• Design full-color illustrations

When shopping for video cards, remember that your monitor and computer must be capable of supporting the card you choose.