I\'ve updated a default template in Visual Studio 2008 with the following path:
C:\\Program Files\\Microsoft Visual Studio 9.0\\Common7\\IDE\\ItemTem
I had the same issue. What was here did not work for me. What I did however is to go to a specific folder and edit the files directly. Just go there :
%AppData%\Microsoft\VisualStudio\{some_version}\ItemTemplatesCache\
It contains folders named after the zip files from your archives in the template folder. I needed admin priviledge for edits.
Enjoy.
Open up the Visual Studio Command Prompt and type in:
devenv /installvstemplates
Source: How to Edit Visual Studio Templates