KMS (Key Management Service) is a legitimate technology used by large organizations to activate volume-licensed software locally on their own networks. Third-party "activators" like
Key Management Service (KMS) is a legitimate Microsoft volume licensing technology. Large organizations use KMS to activate multiple installations of Microsoft Office and Windows on their internal network without needing individual product keys for each machine.
Unfortunately, I decided to try the "Microsoft Office 2007 KMS Activator" out of desperation, and it didn't work as expected. After running the tool, my Office 2007 installation became unusable, and I had to perform a system restore to recover.