Adding a memory module to Presario CQ57 Notebook PC?

[FantasticLegs]

I have a question about adding memory to my laptop and I'd really appreciate any help.

I'm using Compaq Presario CQ57 Notebook PC that comes with 4 GB of memory module and one empty memory slot. I tried to put an extra module into the empty memory slot. The memory module is physically exactly the same size as the 4 GB module that already is in place, but I can't fit the extra module into the empty slot. It goes halfway in and then gets stuck. Is there some button or spring I was meant to unlock first, or does the extra module really need to be physically smaller/thinner?

HP's own website says "To release the RAM memory, use a small wooden tool, or fingernail, to spread the clips holding the ends of the RAM memory in place. One side of the RAM memory will rise when the clips are released" and "Place the gold contacts into the connector (bracket) and gently, but firmly, press the RAM memory into place. The clips will click when the RAM memory is properly seated".

None of this helps, because unlike in HP support center's picture, in my laptop the slots are partly overlapping instead of side to side and as I said, spreading the clips doesn't help, the module still gets stuck.

[arbyd]

First, make sure you have the correct memory module, and the correct orientation. PC2 and PC3 SODIMM modules are the same size, but have different keying. See http://en.wikipedia.org/wiki/SO-DIMM for details and a picture.

Slip the module into the connector, with the module tilted up at an angle from the board. After the pins are all the way into the connector, pivot the module down until the clips engage. Crucial has step by step instructions with pictures: http://www.crucial.com/install/sodimm.aspx. Per the instructions, you may need to push pretty hard.