That is exactly what it is used for. One primary device (the desktop) and one portable device for the exclusive use of the primary user of the primary device. Ensure you uninstall any Office trial software and activation assistant then reboot prior to attempting the install on either system. plan to buy a PC next January. Can I buy the 2010 Office business version (which permits 2 activations-on my primary PC and my laptop) and install it first on my new laptop and later install it on my primary PC after I buy it next Jan? In other words, does it matter what sequence I install the software?