dell studio no longer recognising graphics card

Now, ok, I don't know what graphics card was in here when I bought this laptop, but I'm pretty sure it wasn't a standard VGA graphics adaptor.  It won't have been anything fancy (no 1GB dual card graphics), but I suspect I wouldn't have been allowed to choose anything that basic!  (this is an i5 core bought around 20 months ago).

The hard drive died on me, but I figured I'd requested a backup cd when I bought this, so I replaced it and reinstalled everything.

ever since then I've been having problems.  It keeps shutting down without warning.

I got a fan in case it was just overheating, but it still does it.  With some investigation (ie, looking at Performance Information) it has graphics as a major issue, so I looked at the Device Manager and saw that it says it's a standard VGA graphics adaptor.

Can you please tell me what graphics card I'll actually have in this machine, and tell me where I can get the drivers for it? 

I'm hoping that it's just that that is causing my laptop to shut down - it does tend to be if I use graphics intensive programmes (eg games), but not all the time...

If it isn't, I won't be happy that my expensive laptop hasn't even lasted 2 years - that definitely isn't sold 'fit for purpose'...and I will expect you to do something about it.

(note: this isn't the only problem with the reinstallation - my Dell Dock has vanished and I can't find it on the disk anywhere)

And no, I don't see why I should pay to get your Support when the problems I am having are your responsibility.