Try this

Code:
Z:\>imp file=exp.dmp show=y full=y

Import: Release 9.2.0.4.0 - Production on Thu Jul 8 18:23:15 2004

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

Username: sys as sysdba
Password:
or

Code:
Z:\>imp file=ptgr02.dmp show=y full=y

Import: Release 9.2.0.4.0 - Production on Thu Jul 8 18:23:15 2004

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

Username: sys@orcl as sysdba
Password: