It sounds like Windows thinks that the D: partition is not formatted. Take a look at it with Disk Management, Start -> Run -> type "diskmgmt.msc". What does it say there about the D: partition?

lesslaw2000, so your D: drive is a DVD writer. The letter D: will be used to access any readable discs, or "media", in the DVD drive. In this case, the use of "No Media" indicates that there is no disc being sensed in the drive. It means no readable optical disc is detected, not that there is no music or movies which are also, confusingly, called media.

Your music and movie files are probably somewhere on the C: drive. Try looking in "My Documents". In the Start menu, upper right, you should have My Documents, My Pictures, My Music. Also, you can look in My Computer in "(your name)'s Shared Documents" or in the C: drive.

Larry, my DVD drive, F:, shows up exactly the same way -- an all blue pie chart with Used, Free, and Capacity all showing 0 bytes -- because there is no disc in my F: drive. This does not affect your PC in any way. It's just Window's attempt to indicate that this is a removable media drive with no formatted media currently installed.

To make the 0's change to something meaningful, you need to put a formatted CD or DVD disc into the drive. The capacity of that disc will be read and displayed along with the amount of used space. If you put a blank disc into the drive, for example a CD-R or DVD-R, it will continue to show all 0 bytes because the media is not formatted. When you burn some data onto a disc, such as music, movies, or data files, then it will become formatted and you will see the capacity and usage of the disc.