I think one if the more stressful shit i saw was a bad driver update that made a specific model laptop completely unable to boot, unless you could get into BIOS to disable audio, then fully purge the audio driver (it was a hidden driver) and do a clean install.

This, with a 5 digit userbase in one location, with most of them having that specific model laptop, while working desktop support. It was practically an IT drive thru at one point.

DoD IT, hell of a way to start out with large scale xD