I ran into a problem a few months back where I found non-admin users on Windows Server 2003 couldn't run batch files in scheduled tasks. I just gave up then as it wasn't important, but I had to find a solution for the same issue today. Didn't have to look far, it turned out:
SYMPTOMS When you run a batch job that runs under the context of a regular user account on a Microsoft Windows Server 2003-based computer, the script may not run. If you run the batch job by using the Scheduled Tasks feature, the following error message may be logged in the Scheduled Tasks log file (Schedlgu.txt): 0x80070005: Access is denied.
CAUSE This issue occurs if all the following conditions are true: • You run the batch job on a Windows Server 2003-based member server. • The batch job runs as a non-interactive process. • The batch job is configured to run under the context of an account that is not a member of the Administrators group. In Windows Server 2003, the Users group does not have Read and Execute permissions to the command processor (Cmd.exe).