Enable .Net Framework 3.5 SP1 on Windows Server 2012

Add .Net Framework 3.5 SP 1 to Windows Server

The .Net Framework feature 3.5 is not installed with Windows 2012 or Windows server 2012 R2 operating systems. Some applications require Framework 3.5 installed as a prerequisite. such as VMware vCenter 5.5.  Some application installers will install the feature during the installation of the application. You can however install the .Net Framework Feature manually. The option to install it as a feature feature is grayed out. The grayed option to install .Net Framework feature is bewildering because it is listed to be installed but not available and Grayed out.

 Enable .Net Framework 3.5 SP1 on Windows Server 2012 R2

I used the following instructions and the screen shots were from the actual installation of .Net Framework feature on Windows 2012 R2.

 The option to install .NET Framework 35 on Windows 2012 and Windows Server 2012 R2 server is grayed out.

Enable .Net Framework 3.5 SP1 on Windows Server 2012

Enable .Net Framework 3.5 SP1 on Windows Server 2012

To install .NET Framework on widows Server 2012, for example as a pre-requisite for VMware vCenter 5 and VMware vCenter 5.5, run the following command to install .NET Framework 3.5 SP1. it will install .NET Framework 3.5 SP1 on Windows 2012 server when the option to do so from the features and Roles server management snap-in is grayed out.

Follow these steps to enable .Net Framework 3.5 SP1 in Windows Server 2012 , they worked for me when installing .NET Framework as a pre-requisite to vCenter 5.5 U2.

1. Open a Command Prompt window with Administrator Privileges

2. type: dism /online /enable-feature /all /featurename:netfx3 /source:d:sources\sxs /limitaccess

Change the “d” in the command to match the drive letter of your DVD/CD drive os the virtual drive that has the Windows Server 2012 DVD ISO mounted.