Actually, can I change the hardware of my notebook?

I asked a salesman in the ComputerExhi 2009 and he said that I cannot change the CPU used of Lenovo x200(maybe a strategy only)...........and I would like to confirm it here.

If I have a Lenovo Y450a, can I change the CPU and VGA card of it?

Thank you very much.

[ 本帖最後由 ccw 於 2009-8-28 20:52 編輯 ]

Would anyone help?