If your Visual Studio 2015 or earlier is not showing newly installed templates, like for example if you install DotNetBar and templates for new forms are not showing up (Office Form, Metro Form etc.) its possible that your settings cache files are corrupted so try closing all instances of VS.NET and go to the VS.NET installation folder where devenv.exe file is.
From command prompt execute:
Devenv /ResetSettings
That should reset the settings and likely show all new templates.