A method and device for securing a removable Attached Computer Module ("ACM") 10. ACM 10 inserts into a Computer Module Bay ("CMB") 40 within a peripheral console to form a functional computer such as a desktop computer or portable computer. The present ACM 10 includes a locking system, which includes hardware and software 600, 700, to prevent accidental removal or theft of the ACM from the peripheral console. While ACM is in transit, further security is necessary against illegal or unauthorized use. If ACM contains confidential data, a high security method is needed to safeguard against theft.