Windows 10 on pc that has already windows 8.1

[mikezu]

Im buying new windows, windows 10. I've been using my friends windows 8.1 for 3 years and i didnt activate that still has been working 3 years with that notification that says "activate windows" and my computer is REALLY slow. when i got this pc it probably took 30 seconds to it was ready to go now it is like 7 minutes. So if i buy that operating system from local computer store and press this option from my pc that "remove everything and reinstall windows" and then i need to give that activation key which is my windows 10 that im going to buy. So does my pc try still reinstall windows 8.1 or does it upgrade to windows 10 since im giving windows 10 activation key to this pc.

 

[USAFRet]

Im buying new windows, windows 10. I've been using my friends windows 8.1 for 3 years and i didnt activate that still has been working 3 years with that notification that says "activate windows" and my computer is REALLY slow. when i got this pc it probably took 30 seconds to it was ready to go now it is like 7 minutes. So if i buy that operating system from local computer store and press this option from my pc that "remove everything and reinstall windows" and then i need to give that activation key which is my windows 10 that im going to buy. So does my pc try still reinstall windows 8.1 or does it upgrade to windows 10 since im giving windows 10 activation key to this pc.

Assuming you are booting from the DVD (or USB) you bought, and it is a valid Win 10...it will boot from that and not try to start up your 8.1.