|If you see no video from the computer at all on the monitor when you attempt to boot the computer, and if you have more than one video port that it can be plugged into, if you're sure it's plugged into the right video port....|
no video is a common symptom and doesn't necessarily indicate there is anything wrong with your video adapter - usually something else is wrong.
Tell us the make and model of your brand name system, or if you have a generic desktop system, the make and model of the mboard.
The specific model of a brand name system is shown on a label on the outside of the case somewhere, or it can often be determined by going to the brand name's web site and loading a program they have available, if Windows is still working, on the subject computer.
If you have a Dell computer......
Go here for how to find the Service tag "number":
Tell us what it is.
If you have a HP or Compaq computer.....
Scroll down a bit.
Look for the similar label on the outside of your computer.
Quote the specific model number - that's at the end of the first line.
Quote the Product number - that's on the third line.
The model, sometimes the make, of a mboard in a generic desktop system is usually printed on the mboard's surface in obvious larger characters, often between the slots.
Tell us what you see and hear and what you don't.
Does the Power led light up ?
If it does, is it on steady, or is it blinking ?
Does the hard drive activity led light up and blink ?
Do you hear the hard drive spinning ?
Do you hear one or more fans spinning ?
Do you hear any beeps from the mboard other than the normal one short beep, or do you not hear any beeps ?