i can't remember all the details, but i posted them in a support message from the Microsoft web site on the original Compaq IA board, last year. the IA holds a backup image of it's factory software on the second partition of the internal SanDisk, and there's a diagnostic screen that allows you to input a "magic" keyword to restore the factory image, effectively erasing everything to OEM status.
[10 minutes later...]
all the magic words (FIXIT, HAMMER, MURMUR) are described at this Microsoft link:
http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B279064
These codes are:
FIXIT - gives access to advanced dialing settings; also lets you change the password that is stored on the device and used for automatic login. (See: Q278481 - MSN Companion Troubleshooting Tool FIXIT)
HAMMER - resets all dialing settings (See: Q274364 - MSN Companion Troubleshooting Tool HAMMER)
MURMUR - removes all of the current user's information, and reset the device so that you can use a new Member ID. (See: Q279037 - MSN Companion Troubleshooting Tool MURMUR)
See the article on each secret code for more details.