Better option is to go into control panel > user accounts and select "Turn User Account Control On or Off" and Turn it Off, it's a bothersome added security measure that's really only of help protecting complete newcomers to computers.
You'll have to reboot but on the plus side, no more pesky "are you sure you want to run this program" boxes from windows.
Then you'll have no problems editing myinfo.ini files or even saving textures. (It was happening to me)
"It takes two to lie, one to lie, and one to listen."