is this being called from a Bat file or a vbs file? Also, are the the files located on the CD or did you copy them down before starting your setup?
Lastely, for the post, did you type this out or copy and past what you use? The reason I ask is that I find a couple problems.
QUOTE
SYSTEMDRIVE%\files\i386\winnt32.exe /unattend: SYSTEMDRIVE%\files\i386\:\unattended.txt /s: %SYSTEMDRIVE%\files\i386 /syspart: C: /tempdrive:C: /makelocalsource
Updated
QUOTE
%SYSTEMDRIVE%\files\i386\winnt32.exe /unattend:%SYSTEMDRIVE%\files\i386\unattended.txt /syspart:C: /tempdrive:C: /makelocalsource