I have an hp media center computer and i used the retail upgrade dvd to
upgrade.
if like me you found "bits and pieces" of software,old files,etc .software
not working and a general mess with your system,i decided to do the double
install of vista.
now i have a brand new clean ,proper functioning system.no pieces of hp junk
or other junk and to those of you who are sceptical about activation , no
problem activating on line even though this upgrade was activated with the
product 3 times before.
so do a clean install.you will see the difference.