Hello, Illmenia.
Yes, very often activation disappears after updating the BIOS firmware. This is an activation server bug. Try this way:
- Run the command prompt as an Administrator and run the commands
slmgr.vbs /ipk <ProductKey>
slmgr.vbs /ato
where <ProductKey> is a 25-digit unique product key in the format XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
- After completing step 1, restart the PC and check the activation status after 5-7 minutes.
If there is still no activation, then you need to contact a Microsoft support specialist directly in the chat. To do this, log in to your personal Microsoft account on the page https://support.microsoft.com/en-GB/home/contact?SourceApp=smc2&ContactUsExperienceEntryPointAssetId=www.microsoft.com
In the search bar, type (without quotes) "agent support" and press Enter or click on Get Help. Ignore the search results, and click on the "Contact Support" button at the bottom. On the next page, select "Windows" and "Technical Support" from the drop-down lists, and then click on "Confirm". Next, select the chat "Chat with a support agent in your web browser" and on the next page, enter (if requested) your email address and click on "Confirm". A chat window will open in a new tab. Wait for the specialist's response and describe your problem (to speed up the process, you can send a link to this discussion). After checking the license, activation will be restored.