Install .NET 3.5 Windows 8.1

I've been trying to install .NET Framework 3.5 on a Windows 8.1 computer without any luck. I tried the basic approach of downloading and installing it from MSDN which failed saying it couldn't connect to the internet.

Then I tried dism as explained in several forum posts:

Dism.exe /Online /Enable-Feature /FeatureName:NetFX3 /All /Source:E:\sources\sxs /LimitAccess

but I keep getting an error:

Error: 0x800f081f
The source files could not be found.

and in the log file I found something weird:

Encountered an unknown option "source" with value "E:\sources\sxs"

I also tried copying the sxs folder to c:\temp\sxs and putting this in the source.

According to this blog post it isn't possible to install .NET 3.5 after a language pack has been installed. Is there any known workaround to this by now? Danish is the only available language. I'm not able to switch back to English or even install an English language pack.

There is a known way to do it. You have 2 ways. If you have a DVD with the second language that you have installed, copy the SxS folder from this 2nd DVD to the folder c:\temp\sxs or downlaod the MUI pack of the language that you installed and extract the LP.cab also in the folder c:\temp\sxs with expand.exe which is part of Windows.

Now you can run the DISM command and Windows will find the files for both languages.

I had the same problem. The standard solution didn`t work.

After I removed every .NET based security update, it was possible to install the .NET Framework 3.5. Afterwards I reinstalled the removed updates again, and everything was fine.

Found link that identifies two Windows Updates as the problem if DISM and the offline installer do not work. Uninstall KB2966826 and KB2966828, then try installing 3.5 from programs and features. It worked for me.

By Chris Wardario