Update: fixed 3 machines in one Tuesday and one of them was a real stumper
Had a client drop off three laptops on a Tuesday, two were easy wins (bad RAM stick and a dead drive), but the third one had me stuck for a bit. The thing would boot into Windows fine but would randomly freeze every 20 minutes or so, and event viewer showed nothing useful. Turned out to be a failing CMOS battery causing the clock to drift, which confused a license check on their work VPN client. Swapped the $2 battery and it ran for two days straight with no issues. Anyone else run into weird stuff like that where the real cause was way simpler than it looked?