I can't enable offline file

hi everybody
i have one machine in the company domain that i can't enable the offline
files on it even by the domain admin.
I have GPO which force the offline files but again it doesn't work on this
particular computer
I used to have a problem with this computer earlier because of the Terminal
service which I disabled later, it started to work, but whenever I restart
the compute, the checkbox unchecked it self, this problem lasted for one week
I guess then the check box turned into gray
I thought it's because of lack of space in the C drive so I change the
location of the offline file to saved in D drive again with no effect

I will really appreciate any help