Returning BSOD after apparent fix about 3 months ago.

When I play TF2, after awhile my computer blue screens. I had this issue about 3 months ago, but fixed it by reverting the video drivers to an older version. Here is the previous thread: https://www.techsupportforum.com/forums/f299/bsod-when-playing-tf2-1239078.html

I have not made any changes to my system or drivers since then, and I have been playing TF2 on and off since then without issues until now. Any help with how to resolve this (hopefully for good this time) is much appreciated!

Answers to questions at https://www.techsupportforum.com/fo...ions-windows-10-8-1-8-7-and-vista-452654.html

Windows 7
· x64
· Same as current
· OEM
· I don't know
· Probably about two or three years
· Yes, about two or three years ago

· Intel Core Duo E8500
· AMD Radeon R9 255
· Dell 0C27VV
· I don't know, but it should be the same as other Optiplex 780's

· Dell
· Optiplex 780 (Some parts have been swapped or added)

· Desktop