Upon booting up my computer, my screen dims down. For example, when I boot up to my desktop, sometimes, my desktop display would be dimmed. A few seconds later, the screen would dim to the point that it'll appear as if nothing is displaying (if the monitor is looked at from eye level). However, upon closer inspection, I discovered that my monitor is displaying everything; however, I must look at the monitor at a certain angle to be able to see the icons. Could this be the result of a damaged PCI-E slot or a damaged video card?

Do you have another PC to test the monitor or another monitor to test?

sounds like your video drivers are mesed up.

@mailpup Unfortunately, no.
@angelic00 I used Driver Cleaner Pro to clear out my previous drivers and then reinstalled my video card drivers. However, that didn't seem to work. Also, I can't reinstall drivers now because I can't see what's on my screen.

If you can eliminate the monitor as the problem, the next thing I would look at is the graphics card.

What kind of video card do you use? Expansion slot video card or onboard?

Expansion slot, Nvidia 6800.
I installed a new video card recently and the problems with the same time. When I reverted back to my old card, the problems persisted. Possibly a damaged expansion slot?

Do you have reason to believe you did something to damage the slot?

I don't know. I might have damaged the slot when I installed the video card. It's weird though, because it was working fine two weeks ago (after the problems arose).

I still think the monitor is the most likely suspect.

have you tried re-activating your video drivers desktop color control?