tahanks i have been able to rectify this problem using shutdown abort
my instance is now up and running but the problem here now is when i log in as user system i keep having this page

SQL*Plus: Release 10.1.0.2.0 - Production on Fri Jun 15 21:51:14 2007

Copyright (c) 1982, 2004, Oracle. All rights reserved.

ERROR:
ORA-06553: PLS-213: package STANDARD not accessible


ERROR:
ORA-06553: PLS-213: package STANDARD not accessible


Error accessing package DBMS_APPLICATION_INFO

Connected to:
Oracle Database 10g Enterprise Edition Release 10.1.0.2.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL>

pls is there any problem at all with this