Hi,
installing .NET 3.5 on Windows 8.1 differs from install other feature because you have to specify the location of the files to being installed.
To install .NET 3.5 you need access to a Windows 8.1 DVD especially the \sources\sxs folder.
Let us assumed your CD drive letter is D: then you have to call:
D:\sources\sxs>dism /online /enable-feature /featurename:netfx3 /all /Source:D:\Sources\sxs /LimitAccess
An error which often occured is the following
D:\sources\sxs>dism /online /enable-feature /featurename:netfx3 /all /Source:D:\Sources\sxs /LimitAccess
Deployment Image Servicing and Management tool
Version: 6.3.9600.17031
Image Version: 6.3.9600.17031
Enabling feature(s)
[===========================65.9%====== ]
Error: 0x800f081f
The source files could not be found.
Use the "Source" option to specify the location of the files that are required t
o 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
This error occurs if some files are missing(check C:\Windows\Logs\CBS\cbs.log for “Exec: Not able to pre-stage package: Microsoft-Windows-…”). Typical reasons are:
- The Source DVD has the wrong Version. If Windows 8.1 Update (KB 2919355) is already installed use the newer Version (17031)
- Some Language Packs are installed.
To workaround this error insert the Windows DVD and copy the SXS folder of the source DVD to C:\sxs
robocopy /s E:\Sources\sxs c:\sxs
Also, if Langauage packs are installed (is is the most reason why this error happens), extract the lp.cab files of all installed languages (also the language of the origin Windows DVD) to the C:\sxs folder. To do this insert the DVD with the Language Pack and extract the files each of them.
Check with language packs are installed
PS C:\Windows\system32> dism /online /Get-Intl
Deployment Image Servicing and Management tool
Version: 6.3.9600.17031
Image Version: 6.3.9600.17031
Reporting online international settings.
Default system UI language : en-US
System locale : de-DE
Default time zone : W. Europe Standard Time
Active keyboard(s) : 0407:00000407
Keyboard layered driver : PC/AT Enhanced Keyboard (101/102-Key)
Installed language(s): de-DE
Type : Partially localized language, MUI type.
Fallback Languages en-US
Installed language(s): en-US
Type : Fully localized language.
The operation completed successfully.
And extract the files to c:\sxs
expand d:\de-de\lp.cab c:\sxs -F:*
expand d:\en-us\lp.cab c:\sxs -F:*
After extraction run dism against the local c:\sxs folder
D:\> dism /online /enable-feature /featurename:netfx3 /all /Source:C:\sxs /LimitAccess
Michael
If this does not resolve the problem try also the following: