From minutes to days because if the drive has bad spots it can hang on each area for a very long time.
Formatting is just that and never includes installing Windows. I can boot from my GPARTED CD to partition and format a machine on request but after that the next question invariable is "Where's Windows?"
For a laptop my best advice is to use the onboard restore system or recovery media as installing Windows has become harder over the years.
I have a small blue window on top of Thinkpad wall paper, displaying OFF > ON. The O (ON) and I (OFF) symbols are flickering and it looks like it's reformatting the drive. I wouldn't be surprised as I had a CMOS problem when I got it out of the cupboard and after I replaced the battery, some of my probably inadvisable clicking around seems to have started me down this road. There was one icon with a bunch of squares and an arrow pointing too squares in a straight line and I clicked on it, which I suspect started this process running.
I don't mind if it is reformatting; it would be a good thing to clean down and start again (I only need the unit for a simple application on any old MS OS), but it's been doing it for over a day now and there is no progress indicator.
Should I just leave it to run its course? How long might it take? If I switch it off will I do any damage?
Any pointers would be gratefully received.
As you can tell, I have little (or perhaps less than no) idea what I'm doing!