Problems with Win8 - Need urgent help

I have a Dell 5460 Vostro running on Win 8 64-bit. I was trying to modify a config file in program files but I could not save it even though I am the admin, UAC has been disabled, and the file properties does not indicate read-only. It gives me an error message "you will need to provide administrator permission to change these attributes".

Then I made a mistake by clicking on disabling inheritance and now when I check on the security properties, it says "you must have read permissions to view the properties of this object". In the advanced security properties, it says "unable to display the current owner"

How do I revert the inheritance and get to view the security properties again? After I revert this mistake, how can I save the changes I made to this file?

Also, due to all these difficulties with windows 8, I am contemplating installing windows 7. Is this possible and will the drivers for the vostro 5460 works in windows 7?

Many thanks for your inputs!