First see how much RAM you can upgrade to. There's a max amount of slots on your computer. I'd recommend upgrading to the max, if possible. My comp runs Vista w/ 3 GB of RAM, and I don't have much of any problems with it.
Buying through Dell is gonna be more expensive. I'd recommend shopping around. The main thing you need to keep in mind is that you're looking specifically for laptop RAM. It's different from standard desktop RAM. Also, you need to find out what type (DDR, DDR2, etc) it takes. Odds are, for the age it is, you need DDR2, but double-check on that.
Also, RAM is additive. See how many slots you have (if you have a laptop, you likely have two). And see what RAM sticks you already have. If you have two 512 MB RAM sticks, you'll need to buy 2 1 GB sticks to upgrade to 2 GB (which makes things more expensive, but that's done on purpose).
no subject
Buying through Dell is gonna be more expensive. I'd recommend shopping around. The main thing you need to keep in mind is that you're looking specifically for laptop RAM. It's different from standard desktop RAM. Also, you need to find out what type (DDR, DDR2, etc) it takes. Odds are, for the age it is, you need DDR2, but double-check on that.
Also, RAM is additive. See how many slots you have (if you have a laptop, you likely have two). And see what RAM sticks you already have. If you have two 512 MB RAM sticks, you'll need to buy 2 1 GB sticks to upgrade to 2 GB (which makes things more expensive, but that's done on purpose).