The computer is only a year old and I started having this problem the other day.
My computer boots up, and then my screen goes black. I figured this was my video card, I was wrong. I tried two different cards with the same result. So I uninstalled and booted up my computer. Everything was fine. Fans were working, I could see video and everything. My onboard card's drivers weren't installed.
I rebooted my computer so I could install the onboard card's drivers, and the screen has the EXACT SAME PROBLEM! Even the onboard card has the problem. Once the onboard drivers are installed, the screen is black when booting up after the loading bar.
I can see the gateway screen, and then the loading bar, but once I'm supposed to show up at the logon screen it just goes COMPLETELY black, no cursor or anything.
This is a huge problem for me, since I'm a computer gamer and I can't play anything due to not having a working video card.
To me it looks like a problem with corrupted software. As windows loads up in the beginning but locks up afterwards, the hard drive looks to be working.
If you have another pc at your place, take out the main hdd (containing windows) and install it in a working pc. Then you should be able to see wheither it works or not. Ofcourse do not boot from your drive but the pc's own hdd
By on board card I assume you refer to the integrated graphics on the motherboard. If you have your windows installation disc, try booting from it. If it starts up with the screen working, and starts the install cycle, you might try a repair install of windows option. This will not change or destroy any existing programs or their ability to work with windows. If after windows is repaired, the problem continues, the hardware is you best bet for the cause. I would suggest removing all vid. drivers with something like driver sweeper if you can get it up and working. Windows has basic drivers built in so things will work. Install the vid. card and follow the instructions for an up to date driver install.
If you can boot into safe mode, the issue is a driver problem. Wipe all your drivers and start over. Mix and matching video drivers is definitely going to cause issues. Its definitely not a motherboard issue.
As far as I can conclude from your first post, the no-video problem started when installing the onboard video drivers, no?
If so, only install the drivers for the separate card as you will only use that one. Format your entire windows partition and start with a fresh and clean setup.