For your own My Music (inside your profile) you don't need to be administrator. Non-administrator users can access their own data.
So somerthiing is wrong.
What I should do: make 2 new administratior users in Control Panel (one for dasily use, the second for emergencies if the first one is corrupted. If the one for daily use is fine, copy all your data from your current profile and delete that.
Kees
My Dell Laptop is less than a year old, using Windows 7, 64 bit OS. A few months ago My Music, Pictures & Videos Folders stopped opening: "Is not accessible. Access is Denied." I am the only user and believe I have Administrative user enabled, but not sure. Does anyone know how I can get access back? Hopefully without having to reload Windows.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic