Thursday, October 21, 2010

The workstation driver is not installed.

Sometimes it happens that trying to map a UNC path [net use * \\servername\path] from a WSS or MOSS document library, you get an error “The workstation driver is not installed”.

The problem is often in the startup order of the Webclient service and of MRxDAV which is the redirector for Web Distributed Authoring and Versioning (WebDAV).

First a little technical explaination of how this stuff should normally work in Microsoft Windows.

The Webclient service relys on the user-mode DLL Webclnt.dll which is used to communicates with a kernel-mode file system driver that provides the actual redirector functionality. This system driver is the WebDAV Client Mini-Redirector Driver (Mrxdav.sys). This network redirector sends your requests for file operations (read/ write) from local client applications to the remote computer which is serving the SharePoint document library where the requests are processed. The network redirector receives responses from this remote server ans shows them up in your client explorer window or in you current application (such as Microsoft Word or Excel). The network redirector software creates just the appearance on the client system that remote files are the same as local files and allows them to be used, modified and saved more or less in the same way, even if there are some restrictions.

But sometimes something goes wrong. And the communication between the WebClient service and the background WebDAV Mini Redirector gets broken.

The procedure to put everything back to normal is very simple. Here's a little commandline procedure to fix this problem and solve the “The workstation driver is not installed” error message:
  1. net stop webclient
  2. net stop mrxdav
  3. net start mrxdav
  4. net start webclient

You can also stop & start the WebClient service from the services.msc console, but doing it manually one by one is the only way to start these services in the proper order.

Other useful SharePoint articles:
- EventID 2442
- WSS file locked for editing


  1. Thank you very much for the tip. It worked on three different computers. However, on the fourth one I have an issue. The first 2 steps worked perfectly but when trying to start the mrxdav I get an error message: "System error 2 has occured. The system cannot find the file specified" Do you have any idea how can I fix this? When I try to start the web client via the services.msc I get an error message that the depenency service or group failed to start. Please help

  2. Thank you so much - this worked like a charm! Had been struggling for a while before stumbling upon this site..


Related Posts Plugin for WordPress, Blogger...