This article applies to DESlock+ Full Disk Encryption using the standalone client.  If you are using a workstation that is managed by an Enterprise Server please see this article: KB315 - How do I change my 'admin' users password? (managed)

How to change the Admin password?

When you access the User Management via the Full Disk Encryption tool, you will normally see the following

This interface only allows you to add and remove Normal users because the PC has been started using a Normal FDE user account.

If you start the PC using the Admin user, on a purely Standalone system this is always 'admin' and can not be changed, you will be presented with the following

Clicking 'Change Admin Password' will open the following dialog and allow you to change the password

You will need to provide the current Admin password and save the new Admin password file to a removable disk or network location just as you did when starting Full Disk Encryption.

Once successfully changed, you will need to use this new password if you need to recover or decrypt the system.

Why can't I pick my own?

Because the Admin password is vital to regaining access to your encrypted PC, Why do I need an admin password?, and because it should not be used on a regular basis, it is randomly generated and needs to be saved to a safe location.

This reduces the likelihood that an easy to guess or weak password is used and means that you have a backup copy should you need it. It also ensures the widest compatability in respect of BIOS keyboard support as most systems provide only US English by default.