Product:
Cognos BI 10.2.2 fix pack 7
Microsoft Windows 2008 R2 Server

Symptom:
When user surf to http://biservername.domain.com/ibmcognos they get a windows security login dialog. If they surf to only http://biservername.domain.com they get the standard IIS7 start page.
If the same user surf to http://biservername.domain.com/ibmcognos direct from inside the BI server with Internet Explorer there is no problem.

On both server and client the *.domain.com is added as local intranet in Internet Options.

Solution:
On the Microsoft Windows 2008 server start up Internet Information Services (IIS) Manager program and go to the IBMCOGNOS folder.
Select Authentication.
Select Windows Authentication (that is enabled) and click on Providers link at the right.
Move NLMT to be on top over Negotiate.
Click OK.

Test now from the client laptop computer – now SSO should work.