A friend presented his laptop with a “Just-In-Time Debugger” window that wouldn’t go away.
Ran the usual anti-malware apps to no avail.
Tried some of the dozens of registry edits found in a google search, didn’t work either (and the comments of the pages indicated that many others were having the same problem)
A Microsoft fix attempted to re-enable the Dr. Watson debugger
What I found was that the drwtsn32.exe file was missing from the system32 folder.
I found a drwtsn32.exe file on another unaffected machine, copied it into the system 32 folder on the laptop and rebooted.
Success! The Just In Time popup has disappeared.
Hope this helps somebody else doing battle with the Just-In-Time Debugger.