found the source of culprit... it's my VIA SATA RAID Controller Driver, altho i slipstreamed the driver and loaded up just fine... but it show up as "SCSI RAID" instead of "VIA SATA RAID Controller" under device manager. Tried manual updating driver, and this solved problem. but I dont want to do this every time I reformat, whole purpose behind unattend is "set it and forget it" I've tried changing lines on TXTSETUP.SIF even i tried So far I still couldn't fix it I'ved tried going back with old drivers but it doesnt work with SP2 (alot of errors and crashing) EDIT: viasraid.sys is old driver, and they changed it to viamraid.sys, dunno why they changed the name.