Win2003 has identified "mobile hard disk", but there is no distribution of drive.
Workaround: Insert a mobile hard disk, right-click My Computer, select Administration, enter "Computer Management", click "Disk Management" below "Storage". You can see that there are two disks in the computer, where the disk 0 is a hard disk, and the disk 1 is a mobile hard disk. On the right side of "Disk 1", click Right click, select "Change the drive letter and path", select "Add", select a disk, "OK" to exit.