just a very short post, if you are trying to create a new computer variable on a computer that is in a multi-site hierarchy and the computer object is greyed out like the screenshot below, then you are most likely looking at the computer object on Central in the configuration Manager console.
simply create a new connection in the console to the Primary site (or open that sites console) which the computer is managed by and you’ll be able to modify it’s properties like below
cheers
niall
