To see if it's a settings problem, just mess around the
settings. They usually have a manager for it, either at your system
tray (near the clock) or in Control Panel. If it's neither, right
click on your desktop and select Properties. Select the Settings
tab and play around the settings.
Hardware issues is sometimes obvious. If your PC can't start and
has a beeping error which matches graphics card error, then it's
most likely the card problem.
There will also be other occasions where the graphics card will
produce errors of some sort or no errors but the display is just
odd. It isn't so obvious until someone try out the card on another
system.
