Hi Steve,
The next step is to create another passphrase user to add to the disk. Once you add another user to the disk then you should be able to delete the SSO user and re-create.
Open PGP Desktop (SED) Go to PGP Disk, Encrypt disk or Partition, on the lower right hand corner click on New passphrase user and when creating select 2nd option for passphrase user which this is a passphrase you create. Follow the prompts until the user is created. PGP will ask for a passphrase before adding the user to the disk which this is your SSO user's passphrase on the disk. Previous Windows password.
Once the user is added then you can delete the SSO user and PGP will ask for a passphrase which you'll use the new passphrase user's password just created to remove the SSO user.
Re-create the SSO user and once added to the disk then you can do a reboot and SSO should work.
Windows 8.1 should have the option to change password when using the Ctrl-Alt-Del method.
Check your Group Policy:
GPEDIT.MSC". Under User Configuration > Administrative Templates > System, you will see "Ctrl-Alt-Del Options". You can configure any or all of the 4 policies:
Remove Change Password
Remove Lock Computer
Remove Task Manager
Remove Logoff
Thanks
Anthony