If you need to activate Windows 10, there are safe and legal methods to do so:

A: Very little. Both use similar KMS emulation, but different bad actors bundle different malware. Reloader is often considered even riskier due to its popularity on less-moderated forums.

If you have a .edu email address, check (formerly Imagine). Many universities provide free Windows 10 Education licenses—functionally identical to Windows 10 Enterprise, which is even more feature-rich than Pro.

If you still want to proceed, here's a general guide: