Damn Permissions - help needed

I really like vista but one thing that drives me INSANE is the permissions
bit. Im currently logged on as administrator and yet i am still unable to
delete a file. Ive been into properties and unselected the "Read only"
option, also selected me as the administrator in the "user name" section, but
i can't for the life of me delete the file. god, its so annoying when you get
the error message "You need to confirm this operation" and when i select the
continue button it then goes thru the security bit and then once again says
"you need permission to perform this operation"
i find this extremely frustrating, ive tried all sorts but can't seem to
delete this damn file.
Please, anyone, help me out here before i launch my pc out the window!
thanks...