My computer and upgrading

[Drambar]

Recently i have noticed my computer seems a little slow with running tf2.
i might upgrade some parts of my computer, but i dunno what to upgrade, and what is most efficient to upgrade

Here's my specs
Videocard NVIDIA GeForce 8600 GT
RAM: 3gb DDR II
Processor: AMD Athlon 64x2 Dual Core prossecor ~3.0GHz
BIOS: Phoenix -AwardBIOS v6.00PG

I'm a total NOOB to computers, the hardware part :S
What is the difference betwen CPU and Processor?
and what is a GPU?

 

[PhIxX]

A lot of folks are complaining about framerate drops since the last update. I Think your hardware is fine. Top of the line, no, but certainly more than sufficient for TF2.

I'd download and run CCleaner and spybot if you don't already have them. You might just need a little house cleaning on your machine.

 

[JunK]

the CPU and processor are the same thing, and the GPU is your video card. your video card should be fine (not 100% sure for TF2) but i have the same one and play CSS perfectly with everything on high blah blah blah. and depending on what exact AMD athlon 64 x2 you have (can be anywhere between something like 3000 to 7850) you should be fine and could be just what PhIxX said.
depending on your processor it also depends what you should upgrade. if your processor is good enough you can just upgrade your video card a little bit, but if its really old and worn down it'll bottleneck your video card so upgrading it (and possibly a motherboard) would be best