How can user account permissions be modified in Windows?

Modifying user account permissions in Windows can be effectively done by editing the user account properties in the Control Panel. This method provides a user-friendly interface where administrators can easily access the settings related to user accounts, such as changing permissions, modifying user types (standard or administrator), managing group memberships, and other settings associated with each account.

In the Control Panel, navigating to the User Accounts section allows users to see all existing accounts and make adjustments without the need for complex command-line commands. It is a straightforward approach suitable for users who may not be familiar with command-line tools or technical configurations.

The other suggested methods are either not suitable for this task or are more complex and less user-friendly. While command line tools can be used to manage permissions, relying solely on them might not be ideal for all users. Changing the system registry is risky and primarily meant for advanced configurations rather than simple user permission management. Reinstalling the operating system is an extreme measure and would not only be unnecessary for altering permissions but also would result in the loss of existing data and settings.