When I saw this item for sale, I must have been one of the first to buy it. Seems great in concept, especially if you use hot spots for internet access. I use two different laptops, one for work and one for personal use. One has windows XP Pro, the other just XP. When I plugged the kensington firewall into my USB the first computer, the system recognized that a new piece of hardware was installed and then froze up for a few seconds before the blue screen came up and the system crashed. On the second attempt on my other computer it happened even quicker ( within 3 seconds of plugging it in ). Thankfully I was able to restart both of them and no apparent damage was caused. I have NEVER had anything like this happen with any other device I have ever plugged into my computer. Be very careful before you use this GIZMO!!!