"can't connect to this network"

I have been using this wifi setup for about a year now. I've got a PC, Mac, phone, and tablet, and the PC's connectivity has always been a bit spottier than the other devices, but today it just threw a full-on temper tantrum and has been refusing to connect for several hours, even though I'm posting this from the Mac literally right next to it on the same network.

I have both a USB wifi adapter and a PCI one, and both of them can see the network, but both get the "Can't connect to this network" error when I try to connect to it.

Weirdly, when I first got home and booted it up, it was actually working fine for a couple of minutes before it went down. It's done that in the past too, but usually I just give it a minute and it comes back on. No such luck tonight.

Solutions I've tried:

• waiting for it to turn back on on its own
• restarting the computer
• shutting down the computer, waiting, and turning it back on
• hotspotting with my phone (technically worked, but was so painfully slow it was more frustrating than no internet at all)
• using the hotspot to update my device drivers (no updates available)
• forgetting the network and trying to connect again (still can't connect, but now need to enter security key every time I try)
• network reset: this renamed my wifi adapters from "wi-fi 3" and "wi-fi 4" to "wi-fi" and "wi-fi 2" in the connection manager, but did not solve the problem
• sacrificing a goat to ug-qualtoth (didn't actually, but thought about it)

I did not try resetting the router because 1. none of my other devices are having any problems whatsoever and 2. I share my house with five other people.

Are there any other solutions I can try short of buying yet another wifi adapter and crossing my fingers that it actually works this time?

e: Thanks for the tips. I will attempt them when I get home tonight and report back with success or failure. I did test this morning before I left for work and found that it did not in fact magically fix itself overnight, so... yay for consistency, I guess.