Welcome tlall,
Are you trying to install ADNM with MSDE?
Maybe you could install SQL Express 2005 and use the ADNM standalone installer instead?
Just download and install SQL express 2005 (2008 should work as well), create a database called Avast and specify a password (document it in case you need it later).
Then, during the avast ADNM installation, just specify the sql instance you created earlier "servername\avast" and the password that you created. It should work fine.
If not, let us know any errors that you get, any problems in the event viewer, and we'll help you further.