Graphics card problem - low resolution

i have a Nvidia GeForce FX 5200 graphics card which has worked fine for a year, but now my screen is set at a low resolution and i can't get it back to normal.

In the device manager, the graphics card has an exclamation mark next to it, and in the properties has the following message:

This device cannot find enough free resources that it can use (code 12).

If you want to use this device you will need to disable one of the other devices on this system.

I've had a look and it doesn't seem to be sharing resource with anything else. I've also tried downloading a driver from Nvidia but this hasn't done anything.

I'm not very technical and new to this - please help!!!!!!!!!

 

my guess is that you were running an onboard (built-in) graphic controller before you installed the GeForce card.
when you go to Device Manager and open the Video Controllers drop down, you should highlight each video device one at a time. When you do this, you'l see a little red X on top of the window. Clicking this will disable the selected device. Make sure you've disabled all the devices except the GeForce.
that should do the trick!

after that, you should be able to change your resolution.