I ran it. Nothing showed up as unusual. However, I did solve the problem. I was connecting the new drives to the same SATA ports as the old drives. When I connected one of them to the SATA port that hadn't been used as part of the original array, the S100 VDM reported the original array as FAILED, since the drives were no longer connected, and showed the new array as READY. The OS then booted normally. The trick seems to be that you have to delete the old virtual drive before connecting new drives to the same ports.
A client has a Dell T110 (with a PERC S100 RAID controller) running Windows 2008 R2. The system has two drives: a non-RAID drive (C:) running the OS, and a RAID1 drive (E:) sharing data folders with the network. We need to install new, larger disks for the RAID. I thought that I could back up the data on the existing RAID drive (E:), install the new disks, build a new array in the S100's boot-time virtual disk manager (VDM), boot into the OS, create the new partition for the replaced data drive E:, and copy the data back. This was not the case. After installing the new disks and building the new array (which is reported as "READY (R/W)" during boot, Windows boots all the way to "Press CTRL-ALT+DELETE to log on". After two or three seconds, the system reboots. The same thing happens when I try to boot into Safe Mode. The system DOES NOT automatically boot to the Recovery Console. It never seems to know that an error has occurred and that the system didn't shut down normally. I've booted into the Recovery Console, installed the drivers for the PERC S100, and run Startup Recovery to no avail. Also in the Recovery Console, I've run "chkdsk E:\ /f" (remarkably, the drive letter for the data drive remained the same), and no errors were reported. I've also reinstalled the S100 drivers from the Recovery Console using DISM, but that changed nothing. I've booted to Windows 8.1 PE, installed the S100 drivers, formatted the new virtual disk, copied data to it, and everything works fine. The only problem is when I try to boot from the system drive (which has no problems) with the new disks installed. When I put the old drives back in, the system boots normally with no re-configuration needed. The boot-time VDM automatically remembers the disks and the array. Nothing shows up in the event logs indicating there was an error during the boot. The boot log (ntbtlog.txt), after several boots with the new drives in place, indicates that the system reboots at different points during driver loading. There is nothing consistent in the boot log to indicate what the problem is. The only clue I can see is that, during boot time, the VDM reports the original virtual drive as "NORMAL (R/W)" and the new virtual drive as "READY (R/W)", but I'm not sure about the significance of that difference or if it suggests a solution. I can't find any clues in any logs about what the problem may be. If anybody has any suggestions, I'll be grateful. I'll be especially grateful for off-the-wall suggestions.
SOLVED: Reboot Loop after installing new disks in PERC S100 RAID