removable hard drive permissions

i just reformatted my pc – vista. and i cant seem to get into my removable hard drive which is where ive backed up all my files! ive changed every permissoin possible and sometimes the settings apply fine but sometimes it says access denied.
im an administrator so i dont know why it would happen
Edit: i just turned of user account control and it works
solved
Answer #1
If it was an downloaded “Lite” Vista or something it may not have the correct drivers for removable hard drivers or USB flash drives