Running 8.1.5.0 on NT4

Created a DB using the DB Configuration Assistant, then deleted it with same.

I've checked and it has deleted:

All reference to any datafiles created.
All references in the registry.

However, when I try to create another DB with the same name I get an error that the name is in use by an existing DB.

Where else can I look to find references to this DB and delete them as I need to use this name.