Unfortunately Microsoft have not release patch to fix this issue for windows 7
http://www.techiechips.com/web-folders-web-disk-webdav-problems-on-windows-7/
This below fix is for windows vista only.
http://www.microsoft.com/downloads/details.aspx?FamilyId=17C36612-632E-4C04-9382-987622ED1D64&displaylang=en