What is your windows version and database ?
If windows and maxdb
refer: 967742 - SAP NW 2004s SR2 & SAP BS 2005 SR2 Inst. on Windows: MaxDB
1527332 - MaxDB and Windows 2008 (R2): Phase "Check DDIC password"
Set any random default password and login with default password and set 19920706 during password reset option.
If UNIX n maxdb
http://service.sap.com/sap/support/notes/967741
Divyanshu