So I am trying to Install .net 3.5 on a windows 2012 R2 Server. I have tried via the Add Feature and via DISM both fail.
When trying via Add Features GUI I am using the “Specify Alternate Path” This fails with the error “installing of one of more roles, role services, or features failed”
When trying via an Elevated PowerShell to use DISM I am using the following command.
dism.exe /online /enable-feature /featurename:NetFX3 /Source:d:\sources\sxs
This fails with
Error: 0x800f0906 The source files could not be downloaded. Use the "source" option to specify the location of the files that are required to restore the feature. For more information on specifying a source location, see http://go.microsoft.com/fwlink/?LinkId=243077
The DISM log file can be found at C:\Windows\Logs\DISM\dism.log
I have followed the KB listed above (243077) to set the group policy location for the SXS folder. Rebooted and still the same error. The DSIM log shows the following
Failed while processing command enable-feature. - CPackageManagerCLIHandler::ExecuteCmdLine(hr:0x800f0906)
A quick google shows that a lot of people are having problems with this and that you should uninstall KB2966826 and KB2966828 this server hasn’t got either installed.
I have also tried the offline .Net installer and it says that I must add it via windows features. All commands have been run as an administrator and via an elevated prompt.
While writing this I searched noticed the "Similar Questions" and took at look at this Unable to install .net 3.5 on Windows server 2012
dism.exe /online /enable-feature /featurename:NetFX3 /all
Produced the same error as above.