At all my EBS Servers the "Update für die Microsoft .NET Framework 3.5 Service Pack 1- und .NET Framework 3.5-Produktfamilie (KB951847) x64" or in englisch "Microsoft .NET Framework 3.5 Service Pack 1 and .NET Framework 3.5 Family Update (KB951847) x64" fails to install and/or repetingly respawns as available in Windows Update.
A hint in the connect EBS newsgroup helped me to solve this problem:
At first you need to cleanup the .net environment by running the .net cleanup tool available here:
Then you should reinstall .net 3.5 and .net 3.5 SP1 available on those two links:
The EBS Team has also blogged a valid solution that some might find more easy to use: