I know this is an old post, my apologies. I had this same issue... so I did the above suggestion and set the Logon account for the SQL Server Service in my config manager to use a domain account instead, so my sysadmin users on the sql server could use xp_cmdshell. This worked and fixed the problem, HOWEVER, in doing so it made the SQL Server instance only accessible to the local box. When trying to access through SSMS from a different box I would get a "Cant generate SSPI Context error".

Any Suggestions?

Thank you in advance