Thanks for contacting us. In general, if the installation has completed successfully, you should be able to find the Telerik templates in the "Add New Item" dialog of Microsoft Visual Studio.
In your case I would suggest uninstalling RadControls for WinForms, removing all Telerik.WinControls.*
and also the TelerikCommon
assemblies from the GAC and reinstalling the suite again.
If this does not help, you can take a look at the following KB article which described how to manually integrate the Telerik templates in Visual Studio:
I hope this is helpful. Do not hesitate to write back in case of further questions.
the Telerik team