I want to update this now that there are new operating systems and a new version of emanager.
I ran into this same error when attempting to install the new version of Emanager on Windows 7. I didn't know what to do and I stumbled on this old thread form 2009 in which I helped solve the problem! I got caught up on this solution and went to work on Windows 7.
I got emanager 5.2 to install ok, and after adding the site to the local intranet zone in Internet Explorer, I added the computer to the domain. Boom - I lost access.
Turns out its the App Pool Identity that is the problem on a domain. During install, emanager uses the emanageruser to access the database and as the app pool identity in IIS. Once on a domain, that user account is worthless. here is the fix.
In IIS, click the Application Pool
Locate the emanager app pool, right click and edit advanced settings. From there, change the app pool identity to the local system account.
That's it. I can now access this form a web browser anywhere in the network (domain).
There are no longer any COM Plus Applications listed in Component Services with version 5.2.