Illustrated How to Install RAM Memory Replacement DIMM

There are two good reasons for installing RAM in your system, either you want more total RAM installed, or your current module has failed. It's a simple job, providing you purchase a compatible memory module, almost all of which is in DIMM (Dual Inline Memory Module) form these days. The first task if to remove your old RAM and check the labeling, which is the surest way of making sure the replacement RAM will work. Use both thumbs or two fingers to simultaneously depress the while locking levers on the memory slot, and do it slowly so you don't pop the DIMM up into the air. This particular DIMM was PC-133 non-ECC, but most systems currently in use feature DDR (Double Data Rate) RAM at different speeds.
                        
 I'm holding the replacement memory module up over the slot to align the notches with with slots before installing the RAM. The two notches not only orient the module in the proper direction, they serve as keys to prevent you from installing the wrong type of RAM in the motherboard. The notches on DDR-2 and DDR modules are located differently, and the notches also prevent the installation of older RAM modules that require a higher voltage in the slot. You should always handle DIMMs by the edges, and never touch the gold contacts, because the oil from your fingers can degrade the connection. You can see just below the module to the left that the white locking ears of all three slots are wide open.
                        
Now we actually arrive at how to install RAM on the motherboard. We've already aligned the notches in the DIMM with the slot, and we seat the memory module by pressing down firmly with our thumbs on both ends of the module (right). The while locking ears will rise into place of their own accord if the RAM is installed properly. I took a final shot below just to show the replacement DIMM properly installed, and you can see the white locks on have risen into place on the installed RAM module. There's room on this motherboard to install up to three DIMMs, but mixing and matching brands and speeds has never been good practice, which is why I always try to replace all the RAM in a system when I upgrade the capacity. For laptops, see my guide for swapping RAM modules.