While WinNT/2K and Windows 9x's built-in Label utility lets you change the labels of disk volumes, it does not provide any means for changing volume ids. This utiltity, VolumeID, allows you to change the ids of FAT and NTFS disks (floppies or hard drives) on both Windows 9x and Windows NT/2K/XP/2K3.
Usage: volumeid <driveletter:> xxxx-xxxx
This is a command-line program that you must run from a command-prompt window.
Note that changes on NTFS volumes won't be visible until the next reboot. In addition, you should shut down any applications you have running before changing a volume id. NT may become confused and think that the media (disk) has changed after a FAT volume id has changed and pop up messages indicating that you should reinsert the original disk (!). It may then fail the disk requests of applications using those drives.