Alright, let me try to explain this the best I can. I was unplugging the mini-USB from my Siberia V2 USB headset (the one that connects to the dongle which has the mic and headset jacks). Then my Volume Mixer crashed, causing it to apparently disable Realtek Audio, but when I try to look for anything disabled, nothing with the name Realtek seems to come up. I've tried to change my default playback device, and it won't switch, nor will it disable any playback devices either. I'm honestly not sure what to do.
EDIT: Turns out I managed to solve it myself. Had it playing through the wrong playback device. But I still can't switch the proper one to the default.
EDIT 2: Went into device manager and managed to disable the Realtek Audio Output there which was forcefully taking precedence, and so it made my headset the default. Sorry I wasted a thread like this, but perhaps it's best to leave this up in case somebody else has the same problem?