How to reset NTFS permissions on System drive on Windows 7 or Windows 2008 R2 ?

After Win 2008 R2 was installed, some files on drive C: were not accessible anymore and I was getting “Access Denied”

I tried to right-click/properties on the folders that were not accessible and changed their owner and changed permissions but still some folders were still inaccessible not matter what I did. After some research, it turned out the tool “cacls” that allows one to display or change ACLs (access control lists) can help to reset ACLs.

In Windows 7 or 2008 R2 it is called “icalcs”. To reset files permissions:

1. Run “cmd” as Administrator

2. Go to the drive or folder in question, for example:

cd /d c:

cd /d d:

3. To reset all the files permissions, type:

icacls * /t /q /c /reset

The Microsoft TechNet site has documentation for the icacls command

4. And that’s it!

After that, the files permissions were reset and I could access them back again.


It is possible that “icacls” might fail. For that try to take ownership of the files first.

Just before Step (3), please type the following command:

takeown /r /f *