Installing .NET 3.5.1 on Windows 2012 – Error 0x800F081F

Recently, when trying to install Office 365 Dirsync, I ran into an issue with the installation of .NET 3.5.1 as a feature.  I received the error:

Error: 0x800F081F

The Source files could not be found

Since this was a newly installed server, it was baffling as to what the issue was.  After some troubleshooting, I determined there were two causes:

  1. The windows Component Store was damaged
  2. A hotfix KB2966827 had already been installed that causes this issue.

To resolve these issues, I did the following:

  1. I ran DISM /Online /Cleanup-Image /RestoreHealth to repair the Component Store. (
  2. I determined if KB2966826, KB2966827, or KB2966828 were installed, and uninstalled them until after .NET 3.5.1 was installed. ( After installing .Net 3.5.1, you can safely re-install the hotfixes.

About Gary Cooper

I am a Senior Systems Architect for a small midwestern US consulting company (Horizons Consulting) and I currently am certified by Microsoft
This entry was posted in Uncategorized. Bookmark the permalink.

Leave a Reply

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s