I'm been getting this problem from time to time now, however after I reset the system it went back to normal. What could be the problem?

Hey there Shellfish!

Have you tried setting the resolution lower.. just to see what it does?

Updating the drivers, of course.. you might try, rather than letting Win Update do it, actually getting the Model and Serial numbers off the card you have and go direct to the manufacturer.. they sometimes have a different version than the "generic" one.

I'll mark this one open to encourage all to come and take a look.

Thanks for your patience

Overheating could be the issue. To check that your PC temperatures can be tested by downloading from here:

Download SpeedFan - Access temperature sensor in your computer

Any Flames??

I using GeForce 8800GTS and I think I have the latest driver installed
( 4/30/2009 ) ( v6.14.11.8585 )

Thanks elpmek! I installed speedfan and it display that my GPU is 63c and this is when the air con is on at 21c. Is this the default temperature for a GPU card? What should I do?

63 is clearly hot.

So in my view has to be the Monitor or the Grapics card.

Any chance you can borrow a similar graphics card from friend or family?

Try the latest nVidia drivers (32 bit) from here...

Win XP: GeForce/ION Driver Release 185

Vista: GeForce/ION Driver Release 185

Thanks Arctos! Already had that driver. Now my GPU is at 68c (air con off ) but the funny thing is the temperature is already 50++ before it started increasing.