I just discovered a pointless but well-intentioned feature of my motherboard. If it thinks your CPU fan isn’t running at boot time, it says “CPU FAN NOT RUNNING! SHUTDOWN? Y/N”. Which is nice, except my responses aren’t quite quick enough to actually perform the shutdown in the 2 nanoseconds you generally have in situations like that before the CPU is dead. Fortunately, in this case, my CPU fan actually was running. Which was handy. The trials and tribulations of fitting a memory upgrade, huh? (Oh, and then 2 of my USB ports decided to stop working, but I seem to have fixed that with a reboot…)