|The only significant thing you've told us that helps a little that have haven't told us in the first post in that last post is "the hard drive working".|
We need to know things like....
Does the hard drive led blink for a while after you boot the computer like it normally does while the operating system is loading?
Was the computer working fine before you installed the optional video card?
E.g. if you weren't getting video before, you probably won't get it from the new card either - something else is probably wrong.
Did you UNPLUG the AC cord to the computer, or otherwise switch OFF the AC to the computer , BEFORE and during you installing the video card? If you didn't you mayy have damaged the card.
Did you make sure the video card is all the way down in it's slot, and the fastenining screw for it is installed, before you booted the computer?
If the card was not all the way down in it's slot when you booted it may have been damaged.
If you didn't install the fastening screw, it may have moved upward in it's slot when you plugged the monitor into it - that can damage the card.
In either case, it may not work even after you make sure it's all the way down in it's slot.
Sometimes when you install things you have to unplug something that's in the way, or you may have un-intentionally loosened some connection while installing the card. Did you check to make sure no connections you need were loose or unplugged?
E.g. many mboards require you connect an extra power connector from the power supply to them, other than the main 20 or 24 "pin" main one.
Did you change any of the ram you had installed?
What did you have for video before? Was it a card in a slot, or video built into the mboard? If it was a card in a slot, did you remove the old card before installing the new one, or is the old card still installed?
What port is the monitor plugged into?
The one for the onboard video, or one on the new card, or one on an old card?
E.g. In most cases, if the video card is PCI-E or AGP, you will not get video from the onboard video port because the onboard video is automatically disabled when you install the card.
If the video card is PCI, it will probably disable onboard video if it is in the last PCI slot closest to the middle of the mboard, but it may not if it's installed in another PCI slot.
If the video card is AGP or PCI-E, it may require you connect an extra power connector from the power supply to it - you probably won't get video from the new card if that is not connected.