I was using Firefox to upload a youtube video, but then realised I needed to do something else first, so I cancelled it quickly. All my Firefox windows decided to "not respond". I went into task manager and had a look, and I saw under Firefox.exe was dwm.exe. I read a very brief description what was in task manager about the parent and child threads regarding wait chains ('Analyse wait chain'), and I decided to kill dwm.exe. I thought dwm.exe might have been DrWatson (DrWatson.exe or DrWatson32.exe), so I wasn't certain about killing it. After I did, my entire screen flashed slowly once, and everything seemed to be working fine again. The flashing screen might have been due to the fact I had a full-screen game open which uses a different screen resolution.
I would like to know what might have been using dwm.exe 'under' Firefox.exe, and why it didn't complete its usage/task, causing Firefox to freeze after I used Youtube's X (not the browser window/tab) to cancel the upload.
Edited by Campo1988, 30 October 2017 - 05:06 PM.