TakeOwnershipEx is a portable app that can grant full access to read-only files and folders.

You can use this utility to gain full access to folders and files this includes full access permissions as well. Since most modern Windows versions have TrustedInstaller as the default owner of most files and only granting the majority of users read-only access which can be an inconvenience. TakeOwnershipEx is designed to be a simple no-configuration remedy. It can permit users of the "administrators" group to become owners of files or folders in a single mouse click.

TakeOwnershipEx will also store the history of files/folders you have selected to own allowing you to revert access rights back to the original state. It is a very simple solution to a common issue that many users encounter often.