The NoDriveTypeAutoRun value in the registry is a 4-byte binary data value of the type REG_BINARY. The first byte of this value represents different kinds of drives that can be excluded from working with AutoPlay. The initial setting for this byte is 0x95, which excludes the unrecognized type drive, DRIVE_UNKNOWN, DRIVE_REMOVEABLE, and DRIVE_FIXED media types from being used with AutoPlay. You can enable a floppy disk drive for AutoPlay by resetting bit 2 to zero, or by specifying the value 0x91 to maintain the rest of the initial settings. For information about how to change the registry values, see Using the Registry. A table identifying the bits, bitmask constants, and a brief description of the drives follows:
| Bit number | Bitmask constant | Description |
|---|---|---|
| 0 (low-order bit) | DRIVE_UNKNOWN | Drive type not identified. |
| 1 | DRIVE_NO_ROOT_DIR | Root directory does not exist. |
| 2 | DRIVE_REMOVEABLE | Disk can be removed from drive (a floppy disk). |
| 3 | DRIVE_FIXED | Disk cannot be removed from drive (a hard disk). |
| 4 | DRIVE_REMOTE | Network drive. |
| 5 | DRIVE_CDROM | CD-ROM drive. |
| 6 | DRIVE_RAMDISK | RAM disk. |
| 7 (high-order bit) | Reserved for future use. |
Note For Windows NT, you must restart Windows NT Explorer before any changes take effect.