If you are trying to activate Windows 8.1 today, you are opening a machine to every CVE (Common Vulnerabilities and Exposures) discovered in the last two years.

: A restart is required to finalize the changes to the system kernel. Technical Impact on Windows 8.1

Using activation bypass tools like RemoveWAT poses significant risks to your computer and personal data:

The tool is used to circumvent the Windows Genuine Advantage (WGA) and other activation mechanisms, allowing users to use Windows without a legitimate license key.

Explore that don't require activation.