Recently, we had this problem where long URLs in SharePoint caused Explorer View in Document Library to give this unhelpful mesage: "Explorer View requires Internet Explorer 5.0 or greater and Web Folders". Explorer View was working if the URL was shorter than 256 characters. We did a lot of research and could not find a solution and had to start asking our users to give smaller names to the sites and document libraries so that the URL length did not exceed 256 characters. This was really frustrating and became unacceptable after a point of time. We finally found a solution which involves updating a registry entry on the user's machine. So, without any further adieu, here is the registry entry that needs to be updated: HKEY_LOCAL_MACHINE -> SOFTWARE -> Microsoft -> Internet Explorer -> Main -> FeatureControl -> KB325355_INCREASE_WEBFOLDER_MAXURLLENGTH_TO_260CHAR and add a new DWORD value 'iexplore.exe' and give it a value of 1. You can also save the below as a .reg file and ask the user to run it:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\KB325355_INCREASE_WEBFOLDER_MAXURLLENGTH_TO_260CHAR]"iexplore.exe"=dword:00000001
