Please check the following:

1. is there a folder named 'Templates' in the root of your websites server
(you can use the Choose button right of the address-bar)? If not: create the
folder.
2. are your templates ('file.dwt') in that folder? If not, upload the
template-files
3. do you have administrators rights?
4. If so check the Edit, Administer Websites, Users and Roles, New pages
settings. If not, contact the administrator to do thes next steps.
5. settings should be: check 'use dreamweaver templates' and make the
templates visible to the role
6. You will have to do that for all the user-roles
7. Now click the 'New...' button and in the screen that appears and click the
'Refresh Templates' button.