Are you trying to decide between the versions?

Your PC must be online to verify the key with iolo's servers.

The software will ping Iolo’s servers to verify the license and unlock all Pro or Ultimate features. Key Features Unlocked

Many reputable retailers like Amazon or Newegg sell physical or digital copies that include a unique key.

Automatically monitors your PC and cleans it while the system is idle.

When your computer is idle but powered on, ActiveCare wakes up and performs a series of targeted health checks. It does not interfere with active gaming or heavy workloads, ensuring zero drag on system resources while you are using the machine.

System Mechanic uses a variety of tools to keep your system running at its peak: System Mechanic Professional Review