Installing .NET framework 3.5 on windows server 2012

Solution 1:

You need your 2012/2012R2 ISO mounted or unpacked to a folder as the installation media for .net 3.5 is actually included on the DVD/ISO itself!

Next up, you can install by launching a command prompt (As Administrator) and running the following command:

DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:d:\sources\sxs

(Replacing d:\sources\sxs with C:\users\you\desktop... or wherever you unpack it to!)

The command switches used above do the following~:

/Online targets the operating system you're running (instead of an offline Windows image).

/Enable-Feature /FeatureName:NetFx3 specifies that you want to enable the .NET Framework 3.5.

/All enables all parent features of the .NET Framework 3.5.

/LimitAccess prevents DISM from contacting Windows Update.

/Source specifies the location of the files needed to restore the feature (in this example, the D:\sources\sxs directory).

This works 99.9% of the time, and if it fails - it usually indicates a problem with the BITS/Windows update service - which are actually both used by the DISM (Deployment Image Servicing and Management) tool. To fix that, take a look at This Microsoft Fixit Article . The windows 8 manual instructiosn also work for 2012/2012R2!

Solution 2:

You need your 2012/2012R2 ISO mounted or unpacked to a folder as the installation media for .NET 3.5 is actually included on the DVD/ISO itself.

Next up, you can install by launching a Command Prompt (as an administrator) and running the following command:

DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:Z:\sources\sxs

(Z: indicates the DVD drive)