C:\>db2 connect to sample
SQL1032N No start database manager command was issued. SQLSTATE=57019
C:\>db2start
12/16/2010 17:15:22 0 0 SQL1397N The DB2 service failed to logon.
SQL1032N No start database manager command was issued. SQLSTATE=57019
Actually i am unable to start my instance , pls help me out.