I can only suggest setting up a user account with the same user name and password as what you had before (using the password when you first used the account).
It all depends how the encryption key contained in your personal certificate is generated. If it sticks your password through a one way fixed length hash generator then you may be ok. If it is produced in a random way then I can't see a way around it.
If you have got any ERU disks (like who has), they may contain a backup of your personal certificate.
If anyone has any info how this whole encryption thing works in w2k I would also be interested.
[This message has been edited by tOke (edited 21 April 2000).]