The .Net desktop development is not installed. Modify Visual Studio 2017 installation via Control Panel:
1- Close the Visual Studio if open.
2- Go to Control Panel > Programs > Programs & Features
3- Click Microsoft Visual Studio 2017
4- Click Change.
5- Add .Net desktop development feature
6- Click on Install button
Missed Windows Forms in Visual Studio 2017
Seyed Hamed Vahedi
Tue, 15 August, 2017