Unprompted registry update, system restore and clock change

Hello, not sure if I've put this in the right place, just hoping someone can put my mind at ease here. A couple of days ago I started my laptop and before the option screen (Windows 7 professional dual boot with Ubuntu) it said something about updating registry (unfortunately I cannot remember the exact wording), then just before the log on screen it said configuring windows as if it was the first time I'd used the computer. I found this odd as it has never done it before, slightly worried it is some sort of virus action? Later it crashed and while rebooting a 'safe mode looking' window that I have never seen before came up asking if I wanted to restore the system to an earlier date, I pressed cancel as it was something I'd never seen before and was worried that a virus had taken over... The computer is functioning normally, except that the clock went forward an hour, and I have scanned for viruses with Avast Internet Security which found nothing. I was a bit spooked by the whole thing as I've not seen it do that before, is the 'updating registry' and 'configuring windows' bit to do with windows update?

Lol I know the clocks changed... That was well before this happened. I will carry out your recommendations, thanks.

Hello, thanks for the reply and the welcome! It didn't look like the usual windows update message, especially as it was during bootup not shutdown. However I've pretty much let this one go, done a million scans with Avast, Malwarebytes, MSE, Spybot S&D with nothing found, the computer is acting normally again, and as I can't remember the exact details (date, wording etc) I'm sort of thrashing around in the dark...