I'm running a similar setup on PE2005 with no problems. First boot figures out what the hardware is and runs Conrep then ACU. Second boot does Diskpart, Format, then kicks off WinSetup. Here's my relevant parts; Diskpart command;  DiskPart /s %PATH%\DiskPart.txt > NUL Diskpart;  select disk 0 clean create partition primary select partition 1 Select volume 1 assign letter c select partition 1 active exit Format command;  Format C: /FS:NTFS /Q /V:OS /Y > NUL Setup command;  WINNT32.exe /s:\\%SERVER%\%SHARE%\i386 /unattend:%PATH%\Temp\UNATTEND.TXT /noreboot /syspart:c Drivers section of unattend;  [OEMBootFiles] 	HpCISSx2.inf 	HpCISSs2.sys 	cpqcissm.inf 	cpqcissm.sys 	cpqarry2.inf 	cpqarry2.sys 	symmpi.inf 	Symmpi.sys 	LsiCsb6.inf 	LsiCsb6.sys 	txtsetup.oem  [MassStorageDrivers] 	"Server 2003 Driver for Smart Array SAS/SATA Controllers" = OEM 	"Smart Array 6i, 641, 642, 6400, 6400EM Controllers" = OEM 	"Smart Array 5i, 532, 5312 Controllers" = "OEM" 	"Smart Array 5300 Controller" = "OEM" 	"Compaq Smart Array Controllers" = "OEM" 	"LSI Logic PCI SCSI/FC MPI Driver (Server 2003 32-bit)" = "OEM" 	"CSB-6 Ultra ATA-100 IDE RAID Controller (Windows 2000/Server 2003)" = OEM 	"IDE CD-ROM (ATAPI 1.2)/PCI IDE Controller" = "RETAIL" 	"Compaq Drive Array" = "RETAIL" I specifed the matching .inf files for each driver.   You did write your own custom txtsetup.oem to include all the drivers, right? -Jeff