I am doing a hard disk scan in my program, and I remember the bad old days when scanning B drive would freeze my machine. Can I skip A and B drives for those users that still have floppies? Are A or B drives in Windows ever used for things other than a floppy disk?
It shouldn't matter to you which drive letters are assigned to what kind of drives.
Use GetLogicalDrives to determine what drive letters are assigned and GetDriveType and SetupDiGetDeviceRegistryProperty to determine the type of a drive.