Upgrade Guide

2. Locate the Memory Sockets

Turn off your computer, unplug the AC power (very important if you have a Pentium II­based system), and remove the cover. A Pentium system's memory sockets--white SIMM sockets (A), or perhaps a combination of SIMM and longer, black DIMM sockets (B)--can be anywhere, but they're usually located toward the front of the system as you face it. The sockets of a Pentium II, Pentium III, or K6 machine--almost always DIMM--tend to be near the CPU.

PC memory modules go into sockets in sets called banks. DIMM sockets simply require one DIMM per bank; 72-pin SIMM sockets require two SIMMs per bank. That means you can add or remove just one DIMM at a time, but for 72-pin SIMMs, you'll need to add or remove two at a time from the same bank. Right next to the sockets, you should find labels on the motherboard indicating the sockets' bank numbers (C and D). Fill the banks with the lowest numbers first.