I use this command line to install from a network share: set AnswerFile=i:\WinXP-SP2\unattend.txt set SetupFiles=i:\WinXP-SP2\i386 start /wait %SetupFiles%\winnt32 /s:%SetupFiles% /unattend:%AnswerFile% /tempdrive:c: /dudisable /syspart:c: It was launch from BartPE. I: is a network share.