That’s the error you get for oracle user for whom password is expired.
One Solution – Connect using sqlplus to set new password, you can even use the same password you had earlier.
SQL*Plus: Release 126.96.36.199.0 Production on Mon Dec 13 01:12:07 2010
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Enter user-name: myuser
ORA-28001: the password has expired
Changing password for myuser
Retype new password:
Oracle Database 11g Release 188.8.131.52.0 – 64bit Production