WindowsApps is a special folder where Windows 10 keeps installed apps from the Store. If some day you need to explore its contents to troubleshoot any issues, you'll face the problem that you have no access to the folder. Here is how to resolve the issue.
This folder is hidden, so you need to enable hidden files in File Explorer. Even when visible, the permissions pre-configured for this folder do not allow the user to open it. Once you open it, an error message appears "You have been denied permission to access this folder". If you want to access the WindowsApps folder, you need to adjust its file system permissions. This will require a number of steps from you. You must be signed in with an administrative account to continue.
To open the WindowsApps folder in Windows 10, do the following.
Open the Program files folder (the parent folder of WindowsApps) in File Explorer.
Find the WindowsApps folder in the list. If it is not visible, enable hidden files in File Explorer.
Now, right-click the WindowsApps folder and select Properties from the context menu.
In the next dialog, click the link Change under Owner. You might be asked to enter the password of the Administrator account. Type it when prompted.
Tick the checkbox "Replace owner on subcontainers and objects" and click Apply.
This should be enough to browse the contents of the folder. Open the folder and confirm the UAC prompt:
The folder contents will be accessible:
Please keep in mind that file operations in this folder can break installed Store apps and make them unusable. Do not delete or change anything in this folder unless you know exactly what you are doing.