Need advise/suggestions on my system

[Throbbin]

So a few years back I had a computer retailer build me a system using components I chose personally. I am what you might call a top-tier casual computer aficionado: I know more than most, and less than everyone here. I have a general understanding of how a system works, what each component does, limited proficiency on specs and performance, and a general grasp of terminologies.

Anyways, I had this system built for me back in 2007;

Intel Core 2 Duo E6750 Conroe (2.66 GHz - not overclocked)
Asus P5K Deluxe Mobo
EVGA Nvidia 8800 GTX (Operating on all factory shipped frequencies)
4 gigs DDR2 RAM (Kingston)
LG Monitor - 1680 X 1050 resolution
Corsair HX620W psu
Seagate 500 gig SATA HD
Windows Vista Premium 64-bit

I'm not sure of the case make or model. It's a mid-size case with 1 round and 1 rectangular vent on the left side of the rig, a silver grille covering the entire front of the case (under the optical drive bays), the power button is in the middle of the case, and a screwless HD/Optical drive bay system. (How would i determine the case make and model? I can't seem to find it printed anywhere on the case itself)

I bought the rig in 2007 and it has served me well since. I play Call of Duty Games, and run PS3 Media Server off of it.

However, in the past 6 months or so, the Video Card has been acting up. I'll be playing a game and it the screen will suddenly go black, after which sometimes the entire system will restart on it's own. The Video Card runs very hot, and I think this may have something to do with it. I try to keep the case (relatively) clean, and vacuum the dust out from time to time.

I know the rig is dated and needs replacing. I don't have alot of money, so I'm not quite ready for a brand new system yet. I may consider replacing just the video card if it keeps crapping out on me.

I should mention that I picked up a beat-up but structurally sound Chieftec Dragon Series Computer Case at a rummage sale, and haven't had the time to do anything with it (it needs a MAJOR cleaning). Should I switch to this one instead? It is bigger, and the Chieftec Dragon series cases seem to have a good reputation.

So - my request to this forum is to help me;

A) Figure out what's wrong with my video card
B) Make suggestions on how I can make some upgrades to the rig to get it to last for another 6-months to a year
C) Identify possible bottleneck issues (I'm aware that the DD2 RAM may or may not be bottlenecking the system)
D) Evaluate my system (and hopefully tell me all it's not so bad)
E) Maybe some help with overclocking (both the CPU and the GPU)

Thanks guys. I'll try to figure out the make and model of the case I'm using.

 

[MadAdmiral]

A.) To really help, we need to know what tests you've run. Find some temperature monitoring programs and run them will gaming (or running a diagnostic program like Prime95). Do both the CPU and GPU to be sure. If the temps are too high, look into adding case fans, moving into the new case, or picking up an aftermarket HSF. Check out some of the troubleshooting threads for more ideas on what to check.

B.) It actually looks pretty good. I'd probably look at throwing in an HD 5xxx series card for an upgrade. The run really cool, so using the current case shouldn't be an issue. You should also start looking at overclocking as well. There are a lot of guides out there about it, so read up.

C.) The GPU is always the bottleneck for gaming systems. RAM won't have a big effect. Your CPU would bottleneck some of the larger GPUs (i.e. the HD 5970, or Crossfire/SLI of the HD 5850, HD 5870, GTX 460/470/480/580).