Microsoft support may be able to assist in reactivating OEM licenses under specific circumstances, even if the key is lost. You can try chatting with a support agent to explain your situation. How to Activate Windows 8.1 for Free - wikiHow
: While it's technically possible to use Windows 8.1 without activation, Microsoft encourages users to activate their Windows installations for full access to features, security updates, and support. Microsoft support may be able to assist in
These tools are often flagged by antivirus software. There is a risk of downloading malware if the source is not verified. Microsoft support may be able to assist in