Hello Woip TCS ,
You should not need to transfer the licenses manually when reinstalling Windows. Each Minecraft license remains associated with the Microsoft account that originally purchased or redeemed it.
Before reinstalling the computers, make sure you know which Microsoft account owns each license. After Windows has been reinstalled, download the Minecraft Launcher and sign in on each laptop using the corresponding account. The Launcher should then recognize the owned Java Edition.
If you want to keep existing worlds, screenshots, resource packs, or other local game data, please back them up before reinstalling Windows, as reinstalling the operating system may remove those files.
If the correct account is being used but the Launcher still asks you to purchase the game, check the purchase under that account and contact Minecraft Support for assistance with verifying the license.
Please do not share account credentials, order numbers, or payment information publicly. Thank you so much for your understanding.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.