The floppy disk drive lights and the CD drive or DVD drive lights flash unexpectedly when you use the Win32_EncryptableVolume WMI class to check whether drives are encrypted or not on a Windows Vista-based computer
On a Windows Vista-based computer, when you use the Win32_EncryptableVolume Windows Management Instrumentation (WMI) class to check whether drives are encrypted or not, the floppy disk drive lights and the CD drive or DVD drive lights flash unexpectedly during the query process. This issue occurs even when you explicitly specify the drives to query.
Note: The Win32_EncryptableVolume WMI provider class represents an area of storage on a hard disk that can be protected by using BitLocker Drive Encryption. Only NTFS volumes can be encrypted.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB952009.