How long will I it take to reset my laptop to factory settings?

I have a lenovo (not sure which model ) And literally just felt like wiping it clean so I did

BUT ITS TAKING FOREVER

I THINK ITS BEEN NEARLY 1HR AND I'm AT 20% ! Did I do something wrong? Is it meant to take this long?

And how long approx will it take thank you.

If you are using Win 8 reset it could take up to 8 hours. Best bet is to leave it to reset overnight!

Yo can set BIOS setup to factory setting(Default)

Also If not installed windows 8 you can't clean up.
Please copy your valuable files to another hard disk or pen drive please format and install O/s