BIOS update taking too long

Support Assist wanted to update my BIOS and some drivers. Started two days ago but update stops running when the machine goes to sleep, so I wake it up periodically. It's still washing machining and "Validating." Fan runs, CPU usage is fairly high, with Support Assist and WMI Provider Host most of it. 

Don't want to pull the plug on a BIOS update and gork my machine, but this is getting old...