You can use this Procedure.
Username: root
Password: dreambox
Proceed as follows:
1. Click on START (on Computer). Have the Dreambox 'on'.
2. Click on Run
3. Type “cmd” and enter
4. DOS window will pop up
5. Type “Telnet 192.168.xxx.xxx” where 192.168.xxx.xxx is the IP address of your dreambox
6. Enter your login: “root”
7. Enter your password: “dreambox”
8. Type “passwd” and enter
9. Type new password
10. Type again the new password to confirm