This is a very old piece of information but I still get this question semi-frequently via email so I figured I’d pop it on the blog as well.
Disable FrontPage Authoring in SharePoint
On the server that is running Windows SharePoint Services, locate the site template that you want to modify. Site templates are located in the following folders on the server, where Drive is the drive that Windows is installed on, and where LangID is the language version of Windows SharePoint Services that is installed on the server.
• SharePoint Team Sites: Drive:\Program Files\Common Files\Microsoft Shared\Web Server Extentsions\60\Template\LangID\STS\XML
• Meeting Workspaces: Drive:\Program Files\Common Files\Microsoft Shared\Web Server Extentsions\60\Template\LangID\MWS\XML
For example, if the English (United States) language version of Windows SharePoint Services is installed on the server, the SharePoint Team Site site template is located in the following folder: • Drive:\Program Files\Common Files\Microsoft Shared\Web Server Extentsions\60\Template\1033\STS\XML
2. Open the Onet.xml file that is in the XML folder associated with that site template.
3. Locate the Project Title tag, and then add the DisableWebDesignFeatures attribute.
The following is an example of the Project Title tag with the added attribute:
4. Restart Microsoft Internet Information Services (IIS).
Read it on MSDN.
Disabling FrontPage Authoring in SharePoint