It might be a good idea to buy your 4GB (if that is what you want) all from the same manufacturer , a pack of sticks is always a good idea doing this since you might get a little discount.
The reason for this is that all motherboards run at certain RAM frequencies
for example mine runs with RAM from 267 MHz up to 667MHz
but if your other sticks of RAM are slower than yourbought RAM then you wont get the speed of the ram you bought because ram will slow down to equal the slower speed.
Also look out for what type of ram you have ... there are around four types that i know of , DDR , DDR2 , DDR3 and one other that i cant remember right now.
Your motheroard will only accept the memory which is that type (DDR2 , DDR3 etc)
DDR2 seems to be the most widely used in modern computers or there mobos
I have googled your mobo and the ram seems to be DDR2 but double check , don't go on my word.
You gould possibly get an update on your processor but it seems to be a good one... keep an eye out for new ones though cos i think you might be needing an upgrade pretty soon... if you decide to do this you should get a quad core , especially since you multitask alot.
I would reccomend getting a new graphics card aswell but it is not really needed unless you enjoy games like unreal tournament 3 or any other high powered game. I got an inno3D 9400 GT graphics card for £50 ( 81.86 US dollars )
