I fixed it!!! Thanks to everyone who tried to help :)

I already tried that multiple times and that didn't do anything. Still doesn't work with freshly installed drivers.

Just a quick update, I was able to access another computer to test, and it works on a different computer. Now I know it's my computer, not the capture card, but this is even more confusing. I have no idea what could be wrong with my computer.

Darn, thanks for trying :)

No yellow triangle, shows up as "I-O DATA GV-USB2" under "Sound, video and game controllers"

Oh yeah, I forgot to mention that. It shows up in Device Manager. Does that mean it's not dead? I have another computer I can test it on but I don't have access to that computer at this time. I'll test it when I get the chance.

SOLVED!!!!!

I finally figured out that the capture card stopped working because of an update to Windows 10. As of the Windows 10 April 2018 update, version 1803, you need to change a setting to get this capture card to work. In the Settings app, go into Privacy, then go to Camera under App permissions. You need to toggle "Allow apps to access your camera" to on. After that, the GV-USB2 capture card should show up in OBS, or any streaming program.

I have looked for hours and I can't find anything on any websites that work.

I have a GV-USB2 Capture Card that I use for my Wii and GC. It used to work fine, showing up as a "Device" under "Video Capture Device" in OBS. I didn't use it for a while, and now when I went back to OBS, it no longer shows up as a "Device." I haven't made any changes to OBS or the driver between it working and not working. I have no idea what could have messed up.

I have already tried many things such as reinstalling OBS, restarting my PC, using 32-bit and 64-bit versions of OBS, reinstalling the Capture Card drivers, using a different USB Port, uninstalling my anti-virus, and probably more but I can't think of anything else right now.

I'm sure it's a problem with something other than OBS, because I also tried using AmaRecTV, as suggested by a guide for the GV-USB2, and the device doesn't show up as an input there either.

I would greatly appreciate it if anyone could help me figure out what's wrong. I would love to get this to work so I can record my runs.