Fix one thing... break another

I -was- going to find a community who might help me with my problem, but then I found this place and it's obviously much more constructive to bitch about it than to actually try to fix it. Shame on me for not seeing that right away.

So my HDD died on me, and after some fussing around I ordered a shiny new replacement. So after waiting for the mailman like a proper doggo, I installed my shiny new toy, booted my pc and... on of my monitors now doesn't work.

I don't know why. I tried a new hdmi-cable, I tried a new monitor. my 2nd monitor works perfectly. I updated my drivers and tried a handstand. nothing. For the rest my pc works fine. The new hard disk works like a charm. But why doesn't my monitor work? If I fix it, will my mouse stop working?

I will still chill and play games tonight, but I will be mildly furiously staring at the black screen next to it every chance i get.