Now I had the time to setup an vSphere 5 vCenter on Windows (MS Sql Express DB) and 4 HP servers. Setup was quite easy of vCenter no real issue. Only the SQL Express was a not working directly, but with some Google all issues could be resolved. I have than upgraded all 4 servers from 4.1 to 5 using the iso image. 3 of 4 have been successfully. The last one was not working after the upgrade and I have than plain reinstalled it. After this the environment was up and running. In the next days I will test all basic functions and later on I will test out the new stuff like VSA, DataStore Pools and so on. Keep you in the loop.