Not that I knew of. Maybe you could download the IEAK (Internet Explorer
Adminitration Kit) for IE7 to see whether you have the option there.
Otherwise you could monitor the registry access the with "regmon" from
Windows Sysinternals: http://www.microsoft.com/technet/sysinternals/ProcessesAndThreads/Regmon.mspx
After having recorded the registry key that gets altered when checking
the "open ftp site in Windows Explorer"-checkbox, you could maybe write
your own ADM template: http://www.oreilly.de/catalog/winsyspe/chapter/ch08.html
