UPDATE: Dec 2016 – While the process below works very well, you can eliminate future .NET install problems by installing FEATURES ON DEMAND on your companies WSUS server.

If you are unable to install .NET 3.5 on Windows 8 or 8.1 and end up with errors like 0x800F0906 and 0x800F081F you will find that errors relate to corrupt or limited access to the source files.  In ALL of the times I have tried to get around this, the source has NOT been the issue.

Often you can just install .NET 3.5 by bringing up a CMD window (don’t forget to right click and RUN AS ADMININISTRATOR) and then type either:

Dism /online /enable-feature /featurename:NetFx3 /All /Source:<drive>:\sources\sxs /LimitAccess

or

DISM /Online /Enable-Feature /FeatureName:NetFx3 /All

In my most recent situation I would then error out with 0x800F081F  and the logs would show:

2014-09-10 19:07:54, Error                 DISM   DISM Package Manager: PID=5116 TID=4028 Failed finalizing changes. – CDISMPackageManager::Internal_Finalize(hr:0x800f081f)
2014-09-10 19:07:54, Error                 DISM   DISM Package Manager: PID=5116 TID=4028 The source files could not be found; their location must be specified using the /source option to restore the feature. – GetCbsErrorMsg
2014-09-10 19:07:54, Error                 DISM   DISM Package Manager: PID=5116 TID=4028 Failed processing package changes with session options – CDISMPackageManager::ProcessChangesWithOptions(hr:0x800f081f)
2014-09-10 19:07:54, Error                 DISM   DISM Package Manager: PID=5116 TID=4028 Failed ProcessChanges. – CPackageManagerCLIHandler::Private_ProcessFeatureChange(hr:0x800f081f)
2014-0910 19:07:54, Error                 DISM   DISM Package Manager: PID=5116 TID=4028 Failed while processing command enable-feature. – CPackageManagerCLIHandler::ExecuteCmdLine(hr:0x800f081f)

 

If this is your case, then .NET may have been patched on your machine… but wait, you say, it is not installed so how could it be patched… that is a good question.  If you look at your WINDOWS UPDATES > HISTORY, you may see some .NET 3.5 patches that have been installed.  If that is the case go to PROGRAMS AND FEATURES > VIEW INSTALLED UPDATES (from the menu on the top left) and find them by KB number.  Note that I have found the names of the patches Windows Update History do NOT match what is in INSTALLED UPDATES… go figure.

Specifically I suggest you look for (and uninstall) KB2966826 & KB2966828 .  In my most recent case I only found KB2966828 but after I uninstalled it and rebooted (yes, the reboot was necessary)  I could install .NEt3.5 on my Win8 PC.


48 Comments

Che · October 9, 2014 at 3:30 pm

I can’t thank you enough. Bought a software and could not install cos of this error. CMD prompt code was a quick fix. Thanks

Ben · October 9, 2014 at 12:06 pm

Thanks so much!
For me uninstalling KB2966828 did the trick.

Wes · October 9, 2014 at 9:45 am

Thank You, worked for me!

Ahmad Alkhateb · October 8, 2014 at 8:07 am

This video works with me 2 100%
http://youtu.be/SpWd0xvTEYg

Vins1970 · October 8, 2014 at 4:48 am

Could you help me? I can not uninstall KB2966826. In the control panel, when I select KB2966826, disappears the uninstall button. If I try to uninstall KB2966826 from the command prompt as an administrator, the system responds by saying that the security updates can not be uninstalled.

    Ian Matthews · October 15, 2014 at 5:16 pm

    I have not seen that problem. If it was a recent install, you could try rolling your machine back to an earlier RESTORE POINT. Please let us know how it goes.

RobZ · October 8, 2014 at 3:22 am

Brilliant – 1 Niggle
Uninstalled Update (in my case 2966828),
Rebooted and retried DISM cmd

Failed with exactly same error message !!!

then re-tried to install through the Control Panel and it WORKED!

jha · October 7, 2014 at 2:45 pm

Thank you!

Sharon · October 7, 2014 at 10:51 am

A million thank yous! This article worked for me.

bahman · October 3, 2014 at 10:11 pm

for me, uninstalling KB2966827 did the trick

Paulo Geneses · September 29, 2014 at 9:18 am

Worked for me too!
Thanks, very much!

Adriano · September 29, 2014 at 7:43 am

Thanks, solved my problem.

Andrey · September 29, 2014 at 1:22 am

Excellent! It works for me!
Thank you very much!

SimonP · September 28, 2014 at 8:36 pm

Nice one.
Thanks. Worked a treat.

jmrula · September 22, 2014 at 11:13 am

This solved a problem I’ve been having for a while and have never found a fix for! Thanks so much!!

beguiles · September 18, 2014 at 8:40 am

Hell Yeah! That worked for me. Thanks dude!!!

Questions or Comments?