When running certain applications through the Run Command Line task sequence in SCCM on a x64 Operating System you might find that the task will fail. This is true for applications that in i.e. Windows 2008 Server doesn’t have its own x64 mode. Some commands are not available by default when running in 32-bit mode, for example pkgmgr.exe,servermanagercmd.exe and dcpromo.exe.
To go around this issue, simply disable 64-bit file system redirection in the task sequence when running such applications.
It is also worth to mention that if you are in fact using ServerManagerCmd.exe to install server roles or features, you need to append the success codes on the “Options” tab to “0 1003 3010″ or else your task sequence won’t work.
More info on this can be found at Techblog.