Purchasing genuine retail keys directly from the Microsoft Store or authorized third-party retailers ensures that you own a permanent, legal license that can be transferred across devices and includes official customer support. Summary Conclusion

Use legitimate licenses from Microsoft or authorized resellers. For testing or non-commercial use, consider official evaluation versions or free alternatives (e.g., LibreOffice, or using Windows without activation, which has some limitations but remains functional).

Hacked KMS tools modify core system files and the Windows Registry. This can lead to: