“This problem may occur if AutoMount is not turned on on a computer that is running Windows Server 2003, Enterprise Edition. When AutoMount is turned on, and a new hard disk is detected, AutoMount automatically tries to assign a drive letter and mount the disk”
Open command prompt type mountvol /e to turn on the Automount option for new disks.
Run the New Partition wizard. Format a new volume that does not have a drive letter.
To turn off the Automount option type mountvol /n .
VERY IMPORTANT :
Do not leave the Automout option turned on on systems that have complex storage configurations, such as Storage Area Networks (SANs). On systems where drives are exposed to more than one system, the drives could be exposed to unexpected systems. This exposure could cause these systems to lose data access or could cause data corruption.