Slow motion

I haven’t had a good feeling about everything in my DAW since Windows forced Anniversary on me. I did a day of recording Saturday and left the PC running overnight. I don’t usually do that. Sunday I restarted and everything in Cubase was in slow motion. Click and wait 2 seconds for everything. Unusable. I checked for malware, ran a virus scan; nothing helped. I went back to my last backup and it failed. Found one from Feb 20 which I had to repair the bootrec to get going. Fun day. Now I’m pre Anniversary and I might keep it that way. I wonder what could cause only Cubase to run that way?