Dear Daniel,

thank you for your message.
The problem and error-code that you receive relates to a problem on database level. Just for your information, ADOxx and related tools (it seems that you are not installing ADOxx, but a tool built on top) use a pre-configured SQL user to connect to the database, the ADOxx user "Admin" is an a user maintained by the system itself and does not relate to a SQL user. So the observation that the "Admin" user is not there, is just fine.

The problem to relates to the SQL user ADOxx uses during a) the installation and b) login to tool. Please perform the following steps to fix this issue:

Alternative A: No other ADOxx related product installed (BOC Management Office, OMILAB tools, etc.)
1) Connect to the database instance using Microsoft SQL Studio
2) Navigate to Security -> Logins
3) Delete all users that relate to ADOxx tools (such as ADONIS, etc.)
4) Delete the database of the tool created
5) Re-run the installer

Alternative B: Other ADOxx tools installed and functioning
1) As a safe-solution, we would recommend to run a second database instance (please perform the setup according to the manual http://www.adoxx.org/live/installation-guide-ul1#vista7 - Section: B. Database installation/preparation
2) Re-run installer and select the newly created instance (instance selection window during DB initialization) to create the DB for ADOxx.

In case of further problems, please let us know!