Because the CD-ROM drive is a volume, by default, it is shared as an administrative share on the network. If the value of this entry is 1, the CD-ROM drive is allocated to the user as part of the interactive logon process and, therefore, only the current user can access it. This prevents administrators and remote users (and even the same user at a different workstation) from accessing the drive while the current user is logged on to the computer. The drive is shared again when the current user logs off the computer.
Value Meanings:
'0' = Compact discs in the CD-ROM drive can be accessed by all administrators in the domain.
'1' = Only the user logged on locally can access data on the compact discs in the CD-ROM drive.
Key:[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
Value Name: AllocateCDRoms
Data Type: REG_SZ
Data:(0 = enabled, 1 = disabled)
More info: http://support.microsoft.com/support/kb/articles/q172/5/20.asp
