Error in Installing Business Notification server

we tried installing the BN on the sql - 2000. Later on we decided to move on to sql-2005.

we just uninstalled the sql-2000 and put in sql-2005.

and if we now try to install the BN we get an error that a previous instance of BN still exists.

now the situation is that we can’t uninstall the previous BN, and neither we can install a new one.

Any suggestions ??