Henry
You should not be changing the permissions on those folders, they are not
real folders, they are only Symbolic Links or Junctions. The folder
structure has changed in Vista.
The "C:\Documents and Settings\Default User" is now "C:\Users\Default"
in Vista and the C:\Documents and Settings\All Users\Start Menu is now
C:\ProgramData\Microsoft\Windows\Start Menu.
The folders such as, Documents and Settings, Default User, All Users, etc
are not real folders, they are just Junctions that point to the new location
in Vista. These folders have a shortcut arrow overlayed on them. These
junctions are designed for legacy programs and applications that are looking
for the old location that they were designed to use such as in XP. The
junctions simply redirect these programs to the new location in Vista.
You can see a complete list of the old / new locations on this website.
Why do I get an Access Denied error when trying to open a folder?:
http://www.jimmah.com/vista/Security/junctions.aspx