Blocked access to batch file I am unable to execute batch files to copy backups from SQL Server 2008 R2 hosted on Windows 2008 R2 to a file share.

Error:  


  Access denied


SQL Server Agent service has full control on the soure and destination folders.

This only happens in Windows Server 2008 R2 on my production environment, suspecting additional security controls on Windows Server 2008 causing this issue.
If you are running the batch file through xp_cmdshell you are using a different set of permissions.  Here is the BOL entry for xp_cmdshell.

Basically though if you are running it as a sysadmin then xp_cmdshell uses the service account for SQL Server, not the service account for the Agent.  If you are not running it as a sysadmin then it uses a proxy account.  The proxy account is stored in credential called ##xp_cmdshell_proxy_account##.