A great way to enable the .net 2.0 framework within Windows 8.1 without downloading the files from Windows Update but instead installing from local media (hard drive/DVD).
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:installationMediaDrive:\sources\sxs
- /Online targets the operating system you’re running (instead of an offline Windows image).
- /Enable-Feature /FeatureName:NetFx3 specifies that you want to enable the .NET Framework 3.5.
- /All enables all parent features of the .NET Framework 3.5.
- /LimitAccess prevents DISM from contacting Windows Update (this mean you do not need Internet access).
- /Source specifies the location of the files needed to restore the feature (for example, the D:\sources\sxs directory).
Taken from this Microsoft site.