Reinstalling windows 10

i am having so many issues with p12 and windows 10, from very slow startup to very slow activation when in the dock to login issues when the wrong username appears that maybe I should just reinstall windows.

I read where win10 has a feature allowing the user to either repair or reinstall itself. First, is this a step I should take, since I do not have the original installer (it was an internet upgrade and electronic serial number).

Second, is this even possible within the VM?

Third: if the above answers are yes, how is It done?

I"ve already reinstalled p12, but just copied the VM from my old machine, which did not have these issues to this extent.

 

Reinstalling Windows 10 does not need serial number, as far as I know..

 

Thanks. I validated that my windows is digitally registered and i improved performance by changing my user account to local instead of using the MS sign on; so going to wait a day or,so before I decide whether or not to repair.