I had this strange issue at a client site today. They have SharePoint 2010 and it was working with Explorer View perfectly fine until they installed the WebDav role with Keberos.
Suddenly Explorer stopped working for their users using IE 9+. I was able to reproduce the issue and tried the following:
- Restarting the WebClient Service
- Used 32 bit version of IE
Funnily enough, the client found an old XP box and was able to launch explorer view from there. I think it was somehow related to Keberos and possibly a double hop issue.
I uninstalled WebDev and sure enough, Explorer View started working again!
I will investigate further and update this post.