Screen goes to Sleep after Operating System Loads

[Medianoche]

Hi,
I have a Dell Optiplex GX240 with Windows XP on it.
At first I had a BSOD after installing a CD/Drive. I changed the RAM to a different slot and the computer booted up normally.
I had it working for about 40 minutes and PC worked fine, apart from an incident when PC shut down by itself, with a flash of a blue screen.
This morning I booted the computer again and the OS loads fine but the screen goes to sleep shortly after.
That won't happen when in safe mode.
Do not seem to have any system Restore point previous to this morning and I have rebooted the PC enough times to use Last good known configuration.

Any ideas??
Thanks

 

[MindoverMaster]

Try going into safe mode and remove/reinstall the graphic drivers.

 

[Medianoche]

Graphic drivers... thanks! for some reason I was suspecting the CD Drivers (because trying to install new device) but the device was actually working fine.. It was the screen that was not working properly.

Any way, I rolled back the driver and problem is solved.

Thanks!