adding memory to compaq question

Click "Install Guide" on this page:

Where it says "Turn off the computer, monitor, and all accessories (printer, speakers, etc.)", that means turn off the switch on the back of the computer. The purpose of doing that, is to make sure that the +5VSB power supply is turned off. Some motherboards have a green LED, and the LED is powered by +5VSB. If you see a green LED glowing, it means the power is not turned off.

If you are not sure how to turn off the power completely, unplugging the computer will also achieve the same result. The reason Crucial wanted the cord to remain connected, is the ground wire of the AC cord, helps provide a path for static discharge, and you are more likely to brush against your computer case and discharge any static electricity, into the computer case and into the ground wire. If you touch the computer case, before you touch any components inside the computer, that brings the static level of you and the computer, to the same level.

Try to handle the modules by the edges. At the very least, keep your fingerprints off the gold contacts. The salt in your fingerprints, can affect the metals underneath the gold plating finish. The gold plating is very thin.

Make sure any notches in the module (in the middle of the gold fingers), line up with the plastic key in the DIMM slot on the motherboard. Since it takes a bit of force to seat the memory module, you want to make sure you're inserting the memory the right-way-round. There are two ways to insert the memory, one way being a 180 degree rotation of the correct way, and if the notch doesn't line up with the key, it will never snap into place. Of course, the gold fingers mate with the socket, so no, don't turn it upside down and tell me there are even more ways to plug it in :-)

Paul