Windows generates several logfiles during Windows Setup. You'll need to either use the Windows Recovery Console, or a third-party "Windows on CD" type tool. I use BartPE, a freeware tool from
to generate a working copy of Windows that runs off the CD to troubleshoot this kind of stuff.
Once you get into the system's hard drive, look for \Windows\setupact.log, \Windows\setupapi.log, and \Windows\setuperr.log. Comparing these files between a client that works and one that doesn't may shed some light on this. It gets down to the level of showing which PnP Device ID's it found, and which drivers it loaded for each device.
I had an instance where 2/3 of my RIS downloads failed out of 50 clients in one day. It turned out to be a bad NVidia video driver at the time. You may find you need to switch SCSI or chipset drivers in your RIS download.
The setupapi.log file may show you that your SCSI driver is loading on some clients, but not on others. Sometimes the PC vendors make slight revisions to their hardware, even for machines bought in the same procurement, and sometimes that means a new driver or a higher rev of the driver is needed.
Are you using Windows Setup in RIS (scripted install), or RipREP images (image-based copy)?
