You can download PC Suite from the Nokia website. Which one you use will depend on what region you live. I have installed it and it is quite simple to use the N900 as a modem. Once you install PC Suite you can simply connect the N900 either by the supplied Micro USB cable and click connect to internet. It will bring up a menu with the option to select your carrier for the region, and then connect to the wireless carrier. Does not take long at all to set up, and it has been very reliable for me. I am using T-Mobile USA btw, so YMMV.