Restoring file security permissions in Windows 7

1)Login in administrator account and Right click on file you want to set
2) Go in properties then security
3) Click advanced or edit. To take ownership, you have to go in advanced menu or add user in edit menu
4) To add trusted installer, go in edit then add, click locations and select Computer name
5)In enter object name option, type:  nt service \trustedinstaller and click ok
6) then apply ok
7)you can verify permission from another computer with same as and in same file & set accordingly
8) Thanks