If the CheckDB repair is failing and you have no clean backup (Why oh why oh why????), then there's pretty much no option left. I hope the DB's not too important (I assume not too important since backups were not a priority)

Please run the following and post the full and complete output

DBCC CheckDB (<database name>) WITH NO_INFOMSGS, ALL_ERRORMSGS

You may also want to notify the business owners of this database that there will be downtime, data loss and possibly worse.

To confirm, this is a SQL Server 2000 database?