A. When run via SQL Executive/SQL Agent, the job runs with the NT credentials of the NT user account that the SQL Executive/SQL Agent service is running under. This account needs to have access to the network resources concerned - i.e. shares, files, printers etc.
Check which account is being used by going to control panel/services/startup and checking.
If it is using the LocalSystem account then this has no network access.
Any network resources you do use, make sure they are referenced by UNC name and not a specific drive letter. i.e. \\server1\bcps and not H:\.