File and folder permissions are really important to Windows. Sometimes a user may mess with the permissions causing software or even the operating system to work in an undesired way.
There’s a simple way to solve this kind of problems without headaches, using the ICACLS command.
Launch the command prompt as an Administrator and navigate through the tree of folders you need to fix.
Then launch the command
ICACLS * /T /Q /C /RESET
ICACLS will reset the permissions of all the folders, files and subfolders. After a while, depending on the number of file, the permissions will be fixed.
Sometimes, you may need to take the ownership of a tree of folders. You can use the command
takeown /R /F *
before launching the ICACLS.
Be careful, taking the owenership of system folders may break your operating systems.