M-Tools

Windows has quite a few management tools built in. For example, these tools are found in the "Windows Administrative Tools" folder.
 * Defragment and Optimise Drives
 * Disk Clean-up
 * Event Viewer
 * iSCSI
 * Local Security Policy
 * ODBC Data Sources (One for 32-bit, one for 64-bit)
 * Performance Monitor
 * Print Management
 * Recovery Drive
 * Resource Monitor
 * Services
 * System Configuration
 * System Information
 * Task Scheduler
 * Windows Defender Firewall with Advanced Security
 * Windows Memory Diagnostic

The main tools an average user would use would be:

Disk Clean-up, Defragment and optimise drives, System Information and maybe Resource Monitor.

On the other hand, a system manager would use all of them at least once. Especially Task Scheduduler.