Explanation
Local Users and Groups is a Microsoft Management Console (MMC) snap-in that allows you to manage user accounts or groups on your computer1. If you cannot find it in the MMC console, you can add it manually by following these steps2:
Press Windows key + R to open the Run dialog box, or open the Command Prompt.
Type mmc and hit Enter. This will open a blank MMC console.
Click File and then Add/Remove Snap-in.
In the Add or Remove Snap-ins window, select Local Users and Groups from the Available snap-ins list, and click Add.
In the Select Computer window, choose Local computer or Another computer, depending on which computer you want to manage, and click Finish.
Click OK to close the Add or Remove Snap-ins window. You should now see Local Users and Groups in the MMC console.

Open-source software is software that has its source code available for anyone to inspect, modify, and distribute. Open-source software is usually free of charge and does not require a license to use. Some examples of open-source antivirus software are ClamAV, Comodo, and Immunet12. The other license types are either not free or not suitable for a SOHO PC. Corporate and enterprise licenses are designed for large-scale organizations and networks, and they usually require a subscription fee. Personal licenses are for individual users and may have limited features or support.

Isolating the machine from the network is a good practice when troubleshooting a PC that is suspected of being infected with malware. This can prevent the malware from spreading to other devices on the network or communicating with external servers that may control or exploit the malware. Isolating the machine can be done by disconnecting the network cable, disabling the wireless adapter, or blocking the network traffic with a firewall.

Explanation
The technician should guide the user to update Windows through the built-in "Check for Updates" feature.
This can be done by having the user click in the Search field, type "Check for Updates", and then press the Enter key. This will bring up the Windows Update function, which will search for any available updates and give the user the option to install them.

The systems administrator should clear the application cache12
If clearing the application cache does not work, the systems administrator should uninstall and reinstall the application12 Resetting the phone to factory settings is not necessary at this point12 Installing an alternative application with similar functionality is not necessary at this point12