In my case I couldn’t open explorer view on a SharePoint 2007 library. the resolution was to switch my IE 11 compatibility view to 10, this resolved the issue.
Add the following to the end of the document library url you would like view with file explore WebFldr.aspx replacing the current view page.
for example :
http://yourdomain/sitename/documentlibararyname/forms/view.aspx
http://yourdomain/sitename/documentlibararyname/forms/WebFldr.aspx