Resetting NTFS files security and permission in Windows 7

http://lallousx86.wordpress.com/2009/06/14/resetting-ntfs-files-security-and-permission-in-windows-7/

I was running Vista with two NTFS partitions (C: and D:), then formatted C: partition and installed Windows 7 RC.
The second partition (D:) had some files security set on files and folders.
After Win 7 was installed, some files on drive D: 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 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 D:

3. To reset all the files permissions, type:

icacls * /T /Q /C /RESET

4. And that’s it!
After that, the files permissions were reset and I could access them back again.
Update:

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 *

cacls is a handy tool to change permissions of files “en masse”.
Reference: http://support.microsoft.com/kb/318754