You need to be methodical when installing memory. First you should remove the existing memory modules. SIMMs are held in place by flexible metal clips on each end of the slot. Carefully push the metal clips outward until the SIMM pops free. These clips can be tough. If you can’t do it with your fingertips/fingernails, try using a pointed plastic object to assist you, not a metal one! If you use a screwdriver tip and slip, you could ruin your motherboard.
Grab the SIMM at the ends, angle it a little toward the motherboard and pull it out. Repeat this with each module until they are all removed. When you lay them aside, make sure you keep the pairs together/in order if you removed two pairs.
Now it’s time to install the new modules. Take a look at the modules. You will notice that they have a little cut-out at the bottom corner on one side. This will help you make sure that you insert them the right way.
Insert the first module into the first slot of the first bank at a 45 degree angle, then carefully rotate it to a vertical position. Two plastic pegs on the socket will go through the two small round holes on each end of the SIMM, as the metal clips snap into place. If the pegs don’t line up to enter the holes, the edge of the SIMM is not correctly seated in the slot. If you feel a little resistance, that’s probably due to the tension of the metal clips. But if you feel a lot of resistance and it just doesn’t snap into place, it might because of the cut-out, and you might have the memory modules inserted the wrong way. Repeat this with each module until they are all properly seated.
Now hook everything up again, but leave the cover off for now, so you can test it. After verifying all connections, turn the power on and watch the monitor carefully. If everything went well, you should see the initial BIOS screen and a counter which represents a memory test. Take a note of the final number of KiloBytes (KB). Don’t be surprised if the number is actually a few thousand KB higher than expected. For example, if you installed two 64 MegaByte (MB) SIMMs for a total of 128MB, the number on the screen should be 131,072. That’s because one MB is 1024 KB, and 128MB * 1024 = 131,072KB. If everything looks ok, you’re all set. Put the cover back on and enjoy your faster PC.
Optional: If you filled up only one bank with your new SIMMS, you can now try to install a pair of the old memory into the second bank and see if your computer likes it.
But what if the upgrade didn’t work? The most common problems after a memory upgrade are either a number of beeps or an incorrect display of installed memory. This is your BIOS telling you that it rejected the memory, most likely due to an incompatible memory type installed. Consult with your motherboard documentation and the vendor you purchased the memory from to find out what type of memory is correct for your machine. Just to be safe, remove the memory modules again, make sure that you indentified the memory banks correctly and started with the first bank, and that you seated them correctly – then give it another try.