Computer help forum: Dell Precision M90 - is this a graphics card failure?

My friend sent me his old gaming laptop a while back so I could join him in multiplayer games. The computer has worked for a while, however, there is a problem that is growing more frequent.

I cannot find a definite trigger, but the computer will start hanging up; the fans go full blast, the processor goes from its usual 17-25% usage to full 100%, everything gets more and more lagged down, then the screen is filled with dancing lines and the computer will not respond. I've seen the dancing lines before; in my experience it's a graphics card failure, but I've never seen a failure like this correspond with the processor going full tilt.

This issue hits seemingly at random. It can hit anywhere from 5 to 15 minutes after logging in (but has yet to strike after 20+ minutes of operation), and happens whether the computer is idle or I'm in a game. Connection to the internet does not appear to be a factor.
Not sure if it'll help or not, but for a general idea of the workload, I typically run Skype and Steam together, playing either Team Fortress 2 or Borderlands 2. I've disabled as many background programs as I can and uninstalled as many misc unused programs as I can find that aren't likely to cause problems with their removal. With the way 7 is set up I don't know how to determine what's necessary and what's not.

One of my friends says this issue a virus. Another says it's a graphics card failure. Another says there's a glitch with the fans and they're hogging the processor going full-speed like that. Yet another says it's a driver issue, or multiple drivers, given the age of the computer. My friend who gave it to me says it's easily 5 years if not older.

I'm asking here because I have no money to get it "professionally" inspected and want to know if there's anything I can do on my end, or if this thing's pretty much only good for parts since I can't afford replacements.



Model Specs:
DELL PRECISION M90
Windows 7 Home Premium SP1, 32-bit
2x - Intel(R) CPU T2500 @ 2.00GHz
4.00GB RAM (3.00 usable)
100GB Hard Drive
DirectX 9.0 +
NVIDIA Quadro FX 1500M display adapter, version 7.15.11.7967
Total graphics memory: 1535 MB
Dedicated graphics memory: 256 MB
Dedicated system mem: 0
Shared system mem: 1279 MB

If more information is needed I can post Steam's system spec readout. I don't know how to get more details in Windows 7, my PC expertise lies more in XP.