Vista - explorer /root,%userprofile%

I am trying to create a explorer window rooted at my profile directory. None
of the below lines work. The error is "This file does not have a program
associated with it for performing this action. Create an association in the
Set Associations control panel."

explorer /root,%userprofile%
explorer /root,c:\users\michael
explorer /root,::{5E6C858F-0E22-4760-9AFE-EA3317B67173}

The following do work:

explorer /root,c:\users
explorer /root,c:\users\michael\documents

I am guessing that the profile directory is a virtual directory somehow.

Does anyone know how I can accomplish my goal. Any help is appreciated.