Try this:
1. Right click on file ->properties
2. Security tab will say something like "you must have permissions blabla" ->click Advanced button on the bottom of the window
3. Advanced security will pop up and at the top will say either Owner: (some weird owner name here) or Owner: Unable to display current owner
4. Click change next to the owner line
5. Select user group window will pop up
6. Click advanced on the bottom -> new window will pop up -> click Find Now on the right
7. List of users and groups will pop up ->select administrators and click OK
8. Click OK again to select administrator group
9. Click Apply and then OK
10. You will get pop up msg that will tell you that you have taken ownership of this file (but you are not done yet).
11. Close all windows
12. Right click your file ->properties ->security tab ->advanced button.
13. Advanced security will pop up and now in the Permissions tab click Continue button.
14 Now use Add button and in the top line you will see Principal: select principal ->click on that
15 You will be asked to select user or group so repeat steps 6 to 8
16. Make sure to mark: full control in the Basic permissions section, click OK, then Apply, then OK, OK.
Voila!