Upgrade Ideas

oh yeah and I'm also runnin dual monitors via DVI right now

Hello and welcome to the forums  
Well if your system had an AMD socket,things were different,you could have only upgraded your CPU/VGA,but now,finding socket 939 CPUs is hard;furthermore,since they aren't produced any more,its not worth it too get one.
So what is your budget for upgrading ? and what's your usage ?

usage is for school (computer engineering, electrical engineering, simulation and robotics) as well as general internet usage, moderate gaming, PC is used daily

Budget it varying, I'm lookin at upgrading a bit at a time when i have extra moneys, I just need someone who has kept up with this stuff for some advice, like i said (as you know) a few years can do some damage for what you think you know, lol

Best bet is to find an AM3 board & CPU + DDR3 ram and use your video card for a while longer.

Athlon II X3 440 is a good inexpensive cpu and a decent upgrade from your 4400+.

OK so I re-read and your GPU fan stops...

5770 would work but you would not see much performance gain till you upgraded the Cpu...

You're in a tough spot. I'm all for being frugal, but money spent on that system could be easily wasted. About the only sure thing is a video card. Your CPU and platform will be a serious bottleneck to any modern GPU, but you could still save it (the new GPU) for your next build, so that part would not be a waste.
What PSU do you have? It may limit the power of what you should get, so please let us know.
Although I have reasons to dislike nVidia, it isn't because I'm an ATi fanboi, and your technical applications may benefit from a nVidia card able to do CUDA / PhysX; that being the case, a low-power version of the 9800GT would be a safe choice as far as your PSU is concerned, and would be a big upgrade from what you have now. If your PSU is strong enough though, with the future in mind you may want something stronger like a GTX 260.
If you want to use an ATi card, (i.e. if CUDA is a non-issue), you may safely choose up to a HD5670 with any PSU, as that card uses very little power and doesn't even have an auxiliary power connector. Again though, if your PSU can support a stronger card, a HD5770 is a much stronger choice while not being unreasonably expensive.
You will likely not realize the full potential of any of these cards in your current system. Your next upgrade will need to be a more substantial one, as your mobo, CPU, and RAM will all need to be upgraded; by this time you may also have decided to upgrade your PSU, but we can keep that a separate issue; same with your drives, although if they're IDE, you will certainly want to get a SATA drive as well.

Short answer: The only piece to consider upgrading in this system is the video card. Get a low-power 9800GT or a GT 240 if nVidia, or a HD5670 or HD5570 if ATi. No other upgrade will be required in order to do that. You're better off doing a new build (incorporating the new video card) than trying to add to your existing machine, which, as is inevitable, has become obsolete.

Edit: r-sky, his video card fan is failing, so it must be replaced.

^+1 for jtt283.

For only a GPU upgrade I would look at cards like 9800GT or even up to GTS250 if you have a PSU of 450watts with min 24amps on the +12 volt rail. Those cards are reasonably priced these days, as an example http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I currently have a 400 watt PSU in the comp

In that case (unless it's a Corsair), most likely it is a generic that would not be safe to use with anything stronger than a HD5670 (ATi) or GTS 240 (nVidia).

not corsair, its a dynex

OUCH! For the sake of your system, replace that PSU-shaped object ASAP!
http://www.hardocp.com/article/2008/05/13/getting_best_...
http://www.hardwaresecrets.com/article/Dynex-400-W-Powe...
...and I could have sworn I had another one. Anyway, add $40-$50 to your budget for a competent PSU like a 380W Antec Earthwatts or 400W Corsair.