a reply to the last post....my processor is a pentium 4 3.33 gig with HT tech., thats definately not the problem guy, i'm not computer illiterate. and yes...i play loads of online games, so YES i need more memory. also, i'm ALWAYS multi-tasking, example: playing a game while playing music....so again, yes i need more memory. one more question and i only need a yes or no answer....would a single 1 gig memory stick (maybe along with one of the 256Mb's i already have) run faster then 2 512Mb's? i already found out what type of memory i need and how many pins and all that. my laptop is more like a desktop though, i dont have battery power saving parts such as a intel centrino processor....i dont see why you would want that? all it is, is a slower processor....why would you just buy a slower older processor for cheaper? but whatever, that has nothing to do with my question, maybe i'll make a new post about that later.....thank you all for your responses though, youve been greatly helpful.

no.
ignore below if you only want yes or no answer

dual ram always run faster than single ram esp you got nvdia chipset in your motherboard. however the system detect the slower ram speed, therefore ALL new ram cards will run with your old ram's speed if u add your old ram card into the pc.

go to a website like memoryx or memoryguide.
there you pick the exact model and make of your laptop, and it tells you the specific memory your computer uses, what its maximum is, etc.
i traded in my 2x256 chips for 2x512. i would have gone for 2 GB but my laptop only supports 1. but i got a steep discount on them by trading in the old ones---basically 50% off. of course that could be because in turkey the secondhand laptop business is in high demand, so old parts are worth more comparatively.
it helped alot on cutting down the overall heat and usage of the processor, when video editing, graphics, or playing games. half the time it would automatically shut down from overheating. since upgrading, it's only done it once, after i spent the whole day working in Premiere.

Just go to any PC store to buy one 512MB PC333 Sodimm .

Hey dude...
getting a RAM is not as easy as buying an apple from a superstore..

Every motherboard has specifications and compatibilities with different RAM.
Since you are on a notebook, the RAM you are getting have to be of different model, size, power, and other specifications as compared to the RAM used in a desktop.

Selecting 512MB or 1GB is just the frontline.
Many people didn't realise this, so when they happily bought their new 1GB RAMs home and install and come back to the forums whining that their computers don't boot up, etc..
These happen because they didn't check their compatibility with their motherboards.

This is a very important step for you especially you are getting for a notebook instead.
I'm sure you know RAMs, there are different types...

And you won't wanna waste your money buying the wrong RAMs and crashing your computer..

To improve your computer's performance:
upgrade cpu & chip set for faster computer
upgrade memory to open up more applications ( not install them)