With Windows 8.1 you can either:
a) upgrade to windows 10:
https://www.tenforums.com/tutorials/2267-upgrade-windows-10-a.html
https://www.tenforums.com/tutorials/139745-upgrade-windows-10-windows-7-free.html
b) clean install to windows 10:
https://www.tenforums.com/tutorials/9230-download-windows-10-iso-file.html
https://www.microsoft.com/en-us/software-download/windows10
If you want to upgrade instead of clean install then make sure that you uninstall any of these non-Microsoft software:
a) antivirus
b) firewall
c) drive encryption
If you have important files it is always best to make free or pay backup images before an upgrade:
Examples are:
Acronis
Aoemi
EaseUS
Macrium
Paragon
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Please remember to vote and to mark the replies as answers if they help.
On the bottom of each post there is:
Propose as answer = answered the question
On the left side of each post: Vote = a helpful post
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