You must use the Role Management Tool to install .Net Framework Exception
Hi,
Today I got below error screen when I try to install .Net 3.5 Framework SP1 on my WIN 2008 R2 server .
Dotnet framework installation failed
Reason :-
- Windows 2008 R2 natively ships with the .NET 3.5 SP1 framework.
- So, it wont allow us to run the .Net 3.5 framework setup file.
Workaround :-
- As Windows 2008 R2 ships with the .NET 3.5 SP1, We just need to enable the feature from “Server Manager“.
Steps to enable feature on Server Manager :-
- Click on “Start” button and type keyword “Server”
- Double click on “Server Manager” link
Opening Server Manager
- On the “Server Manager” window, Choose “Features -> Add Features”
Choose features on Server Manager
- Check the “Dotnet Frameowrk 3.5.1 Features” check box
Check the Dotnet Frameowrk 3.5.1 Features
- Restart the server
Hope it helps 🙂
Rajeev Pentyala - Microsoft Power Platform 
I encountered this “error” about two thirds of the way through a vs2008 express install, then the vs2008 install failed. Why in the world couldn’t the vs2008 install have enough since to figure this out before hand; instead MS wastes 45 minutes of my life again.