VIDEO_SCHEDULER_INTERNAL_ERROR and VIDEO_TDR_ERROR BSOD when gaming

I upgraded to Windows 10 from 8.1 a week or two ago, and ever since I have been unable to play games for more than an hour without BSOD'ing. Usually I get a VIDEO_SCHEDULER_INTERNAL_ERROR, but once or twice it has instead been a VIDEO_TDR_ERROR (atikmpag.sys). This happens consistently while trying to play Hearthstone or TERA for extended periods. I know for certain that the last time TERA crashed was exactly at the one-hour mark (because the game alerts you how long you've been playing every hour) and the most recent Hearthstone crash was very near the one-hour mark as well. League of Legends noticeably does not crash my system, but I speculate that is because matches almost never last over an hour, and the game exits to the client after each match.

I frequently clean out junk files and defrag my computer, and frequently use a tool to fix registry errors. I have already gone to NVIDIA's website and installed the latest Win10 driver for my card, and the problem still persists. All three games are played in Borderless Windowed mode.

Any help is appreciated.

I messed up the attachment and don't know how to un-attach something from a post, but the 499.9 KB attachment is the correct one.