When you receive the error “The template you have chosen is invalid or cannot be found.”  while creating a new site based on a template most likely there are features used in the template that you don’t have in your installation of WSS or MOSS.

This could be because they are simply not activated or because the specific flavor of WSS or MOSS has more features than you have.

Resolving this issue is actually quite easy when you follow the steps described below:

• Download the STPInspector from: http://stpinspector.codeplex.com/ (we will use the STP Inspector to analyzes the site template file (.stp) and show its dependencies on the site features and site collection features).
• Install the STPInspector preferably on the server where your installation of WSS or MOSS resides so it can cross reference the site template file’s features against the features available on the server.
• Download the Microsoft Cabinet Software Development Kit (CABARC) from http://support.microsoft.com/kb/310618 (we will use cabarc for creating a cab file again after we have made modifications to the original manifest.xml file).
• Create a folder on your c: drive called cabarc and extract the files from the executable in there (the name is only important if you want to follow this article by the letter).
• Create a new folder on your c: drive called MySiteTemplateName.
• Rename your site template file (.stp file) from for example mysitetemplate.stp to mysitetemplate.cab
• Double click the mysitetemplate.cab file and copy the contents to the folder you just created on your