Im in the process of upgrading from 1gb of ddr2 ram, but im not sure if i should upgrade to 4gb and get a 64bit operating system, or should i just upgrade to 2gig? any help would be appreciated!

If you upgrade to 4gb with a 64-bit OS, you would have to install that new OS, so all of your previous work/programs would be gone... if you are willing to do that, then 4gb is always better than 2gb (assuming your OS can read it all).

What is the rest of your system like? Are you gaming? 2GB may be enough for your applications.

 yer im willing to back up my documents and that, and yes i am into gaming, im upgrading my graphics card to a 8800gt, but im wondering if there is alot of difference between using 2gig of ram compared to 4gig when gaming.

what kind of mobo and cpu do you have?

Id say 4GB is better for gaming, but obviously not necessary. It also depends on what kind of memory you are looking to purchase (i.e. whether your mobo supports 800MHZ ram, 1066, etc.)

 my mobo is abit fatal1ty, and my cpu is core 2 duo e6300 overclocked to 2.5ghz

i'm pretty sure that is a 650i chipset (someone correct me if i'm wrong)...

so your mobo will easily support 800MHz DDR2 ram.

At this point, 4GB would give you better performance than 2GB of ram (however, i'm not sure if your FPS will reflect that much of a difference)... your video card upgrade will also be a huge improvement.

Here is how I see it... if your willing to go through the hassle of installing a new OS, then go for 4GB of ram. It is easy to get a cheap 4GB kit. Make sure you go for 2x2GB sticks though... it will be better than 4x1GB sticks.

 yer i think im gonna go with 4gig, cheers for your help mate.