Issue - we have a system here that was configured to store the OS, Programs on SSD drive C: and the user data on RAID1 E: -- this has been working perfectly. Until now when one of the RAID drives failed. After replacing the drive, the Windows 8 OS assigns the drive letter F: to this RAID1 volume. Since Win 8 expects to find the profiles, etc. on drive E: the system will only boot in Safe Mode.
From Disk Management the drive letter E: is not available so we can't change F: to E: - drive letter E: is not in use anywhere else and we have never used virtual drives on this unit.
The commands - Net Use E:/d and Mountvol E:/d - did not resolve the problem. Neither did editing the Registry \DosDevices\E: