I recently built a computer for a friend and I ran into a really odd issue...
I have everything up to date, including drivers, and it works absolutely fine on my monitor. He came over today to pick it up, and I have a secondary area for computers I built for testing so I figured I'd boot it up and give him a test run so he could see what it was like.
When it starts, the monitor doesn't turn on until windows Is already booted in (No windows login screen, no motherboard screen) and when it does start, it's stuck at a very low resolution - 640 x something, I honestly don't remember the x because I was pretty panicked. I was unable to manually change the resolution, to even select it was entirely greyed out.
I then brought the computer back into my main room and plugged it into my monitor, and it worked just fine. I thought ok, maybe this was just some odd screwup so I brought it back into the other room to test with his monitor, and it went right back to the 640 issue.
My monitor is a 1080, and his is a 1440x900 the only thing I could begin to think is that I set it up on my monitor, and maybe setting it up on a 1080 monitor is somehow meshing with plugging it into a 900 monitor, so I brought it back into my main room, manually set the resolution to 1440x900, then brought it back into the testing room. It still persists.
I can verify that both monitors are working (He was using it before coming to get his new computer) and as I said, all of the updates are recent including drivers and it's 100% functional on my monitor. Any idea what this could be?