Dave Plowman wrote:

Managed to trip the workshop breaker today which crashed out the old PC
running Win7.

When I restarted it, it said 'resuming Windows' and got to the desktop far
quicker than normal. Why?

Hybrid sleep?

When enabled, if PC goes to sleep, it also writes state to disk in case
power is lost, if that happens it's like waking from hibernate, rather
than booting from scratch.