I got a jtagged xbox for use in my bedroom instead of havin to haul the one from downstairs up to my room. I would like to transfer all my dlc and profile to my jtagged one upstairs. I have a hard drive transfer cable. I know that I have to make sure that I'm not signed into any profile when transfering the data to my pc. I was wondering if transfering my files to my jtagged one will mess anything up since my profile that I want to transfer has the newer dashboard. I was just wondering if that dashboard will affect the dashboard on my jtagged xbox.

If you only copy the DLC data then you will not affect the jtaged box. If you Copy over the $systemupdate contents then your jtag box will ask to update and if you accept, you will kill the JTAG.