XXXX computers

I back up my computer at the start of every month. This morning, as an alternative to going out in the freezing Nor.West wind, I decided to do this month's. I don't know what happened but at some stage the system froze (sympathy with the weather?), wouldn't even let me shut down except by switching off, switching back on just took me back to where I had left, without giving the opportunity to reboot.
I think I've got it all back now except for the graphics pad mouse, which isn't working properly. The back up can wait for another day or two.