Why do I get 'This FTP site cannot be viewed in Windows Explorer'?

[cincihal]

I have a FTP site and would like to give Windows users the ability to use Windows Explorer to drag and drop files. I have tested it on a PC that has Windows XP Pro and Internet Explorer 8 and everything works fine, but testing it on a Windows 7 machine with Internet Explorer 9, I can get the initial html page, but when I go to Page > Open FTP site in Windows Explorer, I get a popup 'This FTP site cannot be viewed in Windows Explorer'. Is this a new security thing? Is there a way to fix this?

 

[Anak]

Check this it may help: This FTP site cannot be viewed in Windows Explorer. - Microsoft Answers
It looks like a registry problem. There is one answer after the OP's post, then the last three replies on page two.