IIS 5 & IIS 6
Disable WebDAV protocol on IIS 6.0
Re: Disable WebDAV protocol on IIS 6.0
May 15, 2008 11:00 AM|saneaprodan|LINK
I disabled WebDAV access by prohibiting _vti_aut/author.dll and owssvr.dll from Windows SharePoint Services 3.0 web service extensions. And yes, you are right, disabling owssvr.dll seems to break Office access to the files, while disabling _vti_aut/author.dll
disabled the ability to save the file back to server.
Here are some resources on this:
http://msdn.microsoft.com/en-us/library/ms947858.aspx. Although out of date, they did help me.