Microsoft was one of the original backers of the WebDAV specification, and first started shipping a client in Windows 98, known as “Web Folders”. This client was also shipped in Windows NT4 and 2000.

The original Web Folders client was an extension to Explorer, the main GUI program used to browse filesystems. It works well enough. In Windows 98, the feature might need to be explicitly installed if Web Folders aren't already visible inside “My Computer”. In Windows 2000, simply add a new “network place”, enter the URL, and the WebDAV share will pop up for browsing.

With the release of Windows XP, Microsoft started shipping a new implementation of Web Folders, known as the “WebDAV mini-redirector”. The new implementation is a filesystem-level client, allowing WebDAV shares to be mounted as drive letters. Unfortunately, this implementation is incredibly buggy. The client usually tries to convert http URLs (http://host/repos) into UNC share notation (\\host\repos); it also often tries to use Windows Domain authentication to respond to basic-auth HTTP challenges, sending usernames as HOST\username. These interoperability problems are severe and documented in numerous places around the web, to the frustration of many users. Even Greg Stein, the original author of Apache's WebDAV module, bluntly states XP Web Folders simply can't operate against an Apache server.

Windows Vista's implementation of Web Folders seems to be almost the same as XP's, and so it has the same sort of problems (at the time of writing).

However, there seem to be workarounds for both XP and Vista that allow Web Folders to work against Apache. Users have mostly reported success with these techniques, so we'll relay them here.

On Windows XP, you have two options. First, search Microsoft's website for patch KB90730, “Software Update for Web Folders”. This may fix all your problems. If it doesn't, it seems that the original pre-XP Web Folders implementation is still buried within the system. You can unearth it by going to “Network Places” and add a new network place. When prompted, enter the URL of the repository, but include a port number in the URL. For example, http://host/repos would be entered as http://host:80/repos instead. Respond to any authentication prompts with your Subversion credentials.

On Windows Vista, the same patch KB90730 may clear everything up. But there may still be other issue. Some users have reported that Vista considers all http: connections insecure, and thus will always fail any authentication challenges from Apache unless the connection happens over https:. If you're unable to connect to the Subversion repository via SSL, you can tweak the system registry to turn off this behavior. Just set the key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WebClient\Parameters\BasicAuthLevel from 1 to 2. A final warning: be sure to set up the Web Folder to point to the repository's root directory (/), rather than some subdirectory like /trunk. Vista Web Folders only seems to work against repository roots.

In general, while these workarounds may function for you, you might get a better overall experience using a third-party WebDAV client like WebDrive or NetDrive.