Final answer:
The system tool that should be used to troubleshoot the error where a mobile phone driver was not successfully installed when plugged into a PC is Device Manager.
Step-by-step explanation:
The system tool that should be used to troubleshoot the error where a mobile phone driver was not successfully installed when plugged into a PC is Device Manager.
Device Manager is a built-in Windows tool that allows users to view and manage hardware devices connected to their PC. It can help identify and fix issues with drivers for these devices.
By accessing the Device Manager, the user can check if the connected mobile phone is recognized by the PC, identify any driver issues with the phone, and attempt to update or reinstall the necessary driver.