how to switch profile to different storage device?

when i first got my 360 i didnt have a harddrive so i created my profile on a memory card, how can i switch my profile onto the harddrive instead??

I'm not entirely sure but if you insert the memory unit into the console first. Then go to console settings on the dashboard and go to storage options. From there you can select items stored on the memory unit and transfer them onto the hardrive- the memory units were designed to be able to transfer content between consoles so it is definitely possible.