OK, for anyone who has this problem in the future: I tried literally over 50 procedures to fix the issue, and finally resorted to disabling my graphics card when I’m not playing games. If anyone has the problem only when they’re not playing games like I do, this is a minor inconvenience to pay in order to actually get things done without worrying about the computer crashing.
To do this, go to Device Manager, expand Display Adapter, right click your video card, and click “Disable.” Obviously just do the same thing but click “Enable” before you play a game.
I’m buying a new laptop soon anyway, one not from Toshiba. Their help line can kiss my ass. They charged me $140 before even asking what was wrong with my computer. I got the money back, but that’s just plain unprofessional. The online support site was more helpful than their guy, who struggled to find the English equivalent of every third word he said.