Check for Updates not available

After installing Acrobat 2017 pro the help>Check for Updates drop down menu is not available.

We are using a classic style licensing model for 125 users. All end points are Windows 7 SP1.

After uninstalling Acrobat XI pro and installing Acrobat 2017 pro the Check for Updates option is not available on a few machines.

Most work fine and update as expected when the Check for Updates option is used. We have tried uninstalling and reinstalling with no change.

Only a few do not even show the Check for Updates in the menu.

Any help would be greatly appreciated.

Thanks,

JP