Uninterruptable Power Supply, that is. My mom said it was making a screeching noise, so she turned it off and back on. Ironically, it only affected the machines that had been plugged into the battery backup side of the UPS, and not the surge protector side. Maybe it was that there was too much drain on the battery, so I moved everything but the modem, router, and server to the surge protector. I hope it doesn’t happen again. This problem ruined my 202-days-and-counting uptime on my BOINC zombie.