This Blog Post lists the hotfixes that are currently available for users who are using the WebDAV Feature on Windows 7 SP1 & Windows 8 -based computers to access there
SharePoint Servers. From my experience, most of the Described Problems in over 90% of the posts are fixed with Hotfixes from the following KB Articles:
Slow performance when you connect to a WebDAV shared folder in Windows 8 or Window Server 2012
Windows 7 SP1
You cannot open or save Office 2010 documents on a WebDAV file server on a computer that is running Windows 7 or Windows Server 2008 R2
Cache files are not deleted on a WebDAV client computer that is running Windows 7 or Windows Server 2008 R2
Connection to a DAV server cannot established on a computer that is running Windows 7 SP1
You do not receive an error message when you try to copy an email message that contains invalid characters from Outlook to SharePoint in Windows 7 or in Windows Server 2008 R2
I will update this Blog on a regularly base and suggested to install the latest Versions of the involved components before you take hours & hours of troubleshooting.
If the Problem still appears after you installed these fixes, than go ahead with troubleshooting or involve Microsoft support to help you!
I recommend you to also update the Networking components, you will find the List in the following KB Article which is also updated on a on a regularly base:
List of currently available hotfixes for the File Services technologies in Windows Server 2008 and in Windows Server 2008 R2
You also can use the following Link to update the Windows 7 SP1 Client with all (incl. WebDAV) available Hotfixes post SP1 by installing the hotfix rollup:
An enterprise hotfix rollup is available for Windows 7 SP1 and Windows Server 2008 R2 SP1
I hope I could save you a lot of time of troubleshooting