Error 0x800f0922 installing .NET 3.5 on Windows 8
Solution 1:
Your source parameter is wrong. The files are removed from C:\Windows\WinSxS. You must point to the SxS folder on your mounted ISO/DVDdrive/USB thumb drive:
Dism.exe /online /enable-feature /featurename:NetFX3 /All /Source:DRIVELETTER:\sources\SxS /LimitAccess
Installing the .NET Framework 3.5 on Windows 8
http://msdn.microsoft.com/en-us/library/hh506443.aspx
Solution 2:
I can confirm the behaviour as follows.
Adding the feature ".NET Framework 3.5 (includes .NET 2.0 and 3.0)" through the control panel fails when in a domain using WSUS.
Running the following command, as Administrator, against the original installation media also fails when a language pack is installed, English in my case on a German installation.
Dism /online /enable-feature /featurename:NetFx3 /All /Source:x:\sources\sxs /LimitAccess
The error here is the same as the OP mentioned. "Source not found" normally around the 65% mark.
Also, its not enough to simply switch back to the original language. The installed language pack must be uninstalled and the system rebooted.
After this the above command runs successfully.