A few years ago, I wrote an article explaining how to change the volume serial number.
This program does not work properly now under Windows Vista or Windows 7 unless executed as administrator. Following many suggestions, I updated the tool to support the latest Windows version.
Please note that after you change the serial number you may need to reboot the PC for the settings to take effect.
Download the tool from here: http://rapidshare.com/files/431997166/VolumeSerial_1.3.zip
UPDATE: If you’re using Windows Vista+ make sure you run this program as an administrator.