SSO Service fails to start

Hi there.

I have BTS 2009 Standard running on a Windows  2008 Standard R2. Everything works fine.

Now I installed .Net Framework 4 and SharePoint Foundation 2010 on it and I couldn’t start the Host Instance anymore. I got always the following Error message in the Application Event Viewer:

” The SSO service failed to start. Error Code: 0x80131700″

I use a distributed environment, means SQL is on one server and BTS 2009 on another. Before I installed, BizTalk runs smoothly.

I run the the BTS Best Practices Analyzer, checked the Database … everything looks fine so far.

Any ideas? 

Thanks in advance

wal