add ram to my laptop

SODIMM is a style of RAM that fits in laptops, is all.

Just open up the bottom of the laptop (make sure you're grounded, e.g. no static shocks!) and look for the sticks of RAM in there. Usually all the slots are there, just count how many - it's probably two and the device manager has made a mistake.

Then go to the computer store and get 4GB of SODIMM sized RAM in whichever clock speed your computer can handle, 1066, 1333, etc. Then you just click the old ones out and click the new ones in. Don't touch the contacts.