Many applications are build with .NET 3.5 SP1 libraries. .NET Framework 3.5 SP1 is not a standard Windows 8.1 Feature. Adding this feature can be cumbersome. This method shows the easy way.
1. Start a command prompt with Administrative privileges. You should see this:
2. Place the Windows 8.1 installation DVD in the DVD drive of the computer. It will pop up with a drive letter in Explorer. In this example drive D: is mapped.
3. Type the next command in the command prompt:
C:\> DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:d:\sources\sxs
The process will take a couple of minutes. When ready you can check Programs and Features in Control Panel: