Hello,
Thank you so much for posting here.
Regarding the first question, can Windows 7 successfully ping the file server?
In addition to this, you can check the share permissions and NTFS permissions of the shared folder to see if you have gained user access on win7.
Issues with applying Group Policy for Windows 7 clients,you can check whether some error events are recorded in your system event log. For details, you can refer to the link below for some checks.
Clients can't apply Group Policy on startup - Windows Client | Microsoft Learn
Hope you are doing well!
Bets Regards,
Shujun