We've got all the 32-bit flavors of Windows 2003 flowing without a problem, but 64-bit dies right at the starting gates with a "INF file txtsetup.sif is corrupt or missing, status 21.". The tcpdump reveals: RRQ "d5750.0" octet tsize 0 RRQ "d5750" octet blksize 1456 RRQ "BOOTFONT.BIN" octet blksize 1432 tsize 0 File.not.found RRQ "ntdd5750.2k3" octet blksize 1432 tsize 0 RRQ "d5750.sif" octet blksize 1432 tsize 0 RRQ "\gnet_d5750\i386\txtsetup.si_" octet blksize 1432 tsi File.not.found RRQ "\gnet_d5750\i386\txtsetup.sif" octet blksize 1432 tsi File.not.found We can not find a way to make it look in the amd64 directory, where the txtsetup.sif, etc. are actually located. We're using basically the same .sif file as from the 32-bit install, so perhaps we are missing a setting required for 64-bit? Here is the main part of the .sif file: [unattended] UnattendMode=fullunattended UnattendSwitch=No OemPreinstall=Yes OemSkipEula=Yes FileSystem=* WaitForReboot=No NoWaitAfterTextMode=1 NoWaitAfterGUIMode=1 DriverSigningPolicy=Ignore NonDriverSigningPolicy=Ignore Repartition=Yes [setupData] OsLoadOptions=/FASTDETECT SetupSourceDevice=\device\lanmanredirector\126.96.36.199\install\gnet_d5750 [data] floppyless=1 msdosinitiated=1 OriSrc=\\188.8.131.52\install\gnet_d5750\amd64 #(This was i386, that didn't work. Switched to amd64, that doesn't work either) OriTyp=4 LocalSourceOnCD=1 DisableAdminAccountOnDomainJoin=1 AutomaticUpdates=Yes Autopartition=0 UnattendedInstall=yes Also tried just routing everything for i386 to amd64 with the tftpdremap and just copying everything from the amd64 to the i386 directory. Those get past this point but just have issues later on, so I was hoping to just figure out how to do it the right way.