Install into a mounted volume

When I try to Install the Norton product on my computer running OS Wn 7 64 bit this error window pops up. "You have an invalid or non-existent folder for this Norton product. Please try again." I get this error because when I go to the browse option and browse to the folder I want NIS to install into then I get that error window and message. OBTW I am selecting an install folder which is in a "mounted volume"

If I select any other folder in the default "Programs" folder the error does not pop up.

Does this mean NIS 2010 can only be installed into the WN 7 default "Programs" folder or subfolder?  Any insight will be appreciated. Pete