Chad

I have an odd issue. First let me state that I did a successful upgrade from
MCE 2005 to Vista RTM (official release, from MSDN). My username on the MCE
2005 setup was Chadi. It is also the same now in Vista, with "administrator"
type account. However, I occasionally run into problems where Vista tells me
I do not have administrator rights and need to login as administrator to do
that task / function. Why am I being told this when my Chadi account is
setup as administrator? I do end up logging out and logging in as
Administrator (actual name of account). I'm lost on that, please explain how
I can make my Chadi account 100% administrator entirely.