Post Power Trip Oracle Problem !

[Guest_imported]

Machine: Intel Dual P 200MHz, 256Mb RAM, 4Gb HDD
System: WinNT4, Oracle Server 8.1.5

Hello all,

We have a problem accessing our Oracle Database after a power trip. Logon through SQL-Plus gives the following error:
ORA-01034: ORACLE not available

Attempt to start the database from svrmgrl gives these errors:
--------------------------------
c:\>svrmgrl
SVRMGRL>connect internal
password:
Connected.
SVRMGRL>shutdown abort;
Oracle instance shut down.
SVRMGRL>startup;
ORA-27100: shared memory realm already exists
OSD-00000: Message 0 not found; product=RDBMS; facility=SOSD
SVRMGRL>
-------------------------------

According to the Online Resource, it looks like the previous instance is not shutdown properly. We try stopping the service and starting it again but it does not help. Rebooting the machine won't help either.

What should we do ? Please Help.