.NET Framework 3.5 Installations Probleme

Ich hatte wiedermal Probleme mit einem frischen Server 2012 R2... hier wollte sich das .NET Framework 3.5 nicht installieren lassen.

Hier mal die Anleitung zur Grundlegenden Installation. (Geht mit dem GUI natürlich auch)

1. Open Windows Explorer (Windows + E)
2. Mount the Windows 8 installation ISO you used to install your operating system.  You can do this by right clicking on it and selecting the option Mount. UPDATE: If you have the Windows 8 Installation Disc in your optical drive, then use this instead. However, make sure you change the commands mentioned later to match your optical drive.
3. Use the RUN command in administrator elevated mode. You can do this by navigating to the location c:\windows\system32\cmd.exe and right-clicking on the cmd.exeapplication and selecting Run as administrator.
4. Once the command windows has loaded, then type the following command (Note: Match the drive letter to your appropriate drive letter for the ISO or DVD):

dism /online /Enable-Feature /FeatureName:NetFX3 /All /Source:E:\Sources\SxS /LimitAccess

Hit enter once you have completed the command.

Hier der Regkey der mir geholfen hat!

Looks like the registry key hasn’t been ‘wrapped’ properly. The full key is HKEY_LOCAL_MACHINE\ SOFTWARE\ Policies\ Microsoft\ Windows\ WindowsUpdate\ AU
The value name is ‘UseWUServer’ and should be a DWORD. The value data is 0.
Once .NET is installed, either delete this key, or put the value back to 1.