Quick description of the situtation:
I have a test machine (we need to test our software which talks to BB devices against releases of BES/BES Express) which is running Win Server 08 R2 as domain controller/global catalog (only server in forest). I have installed Exchange 2010 Standard, followed by SQL 2008 Express. Then I ran through the BES Express installer which near the end complained it cannot detect any GC servers and because of this it cannot use Windows authentication. Its running right on one so whats the problem?
I followed the default installation instructions - installed BES as BesAdmin user which is member of Admins, Domain Admins, Domain Users, View-Only Management groups. Everything else was installed as Administrator (member of Enterprise, Domain and regular Admin groups).