It comes with built-in HP un2420 EV-DO/HSPA Mobile Broadband Module ( Integrated mobile broadband module with Gobi global mobile Internet technology provides worldwide connection to both CDMA (EVDO) and UMTS (HSPA) networks ). Vodafone isn't very sure if this is supported on their network.
The OS would be Windows 7 Professional. If the HP un2420 is indeed compatible, do I need to use Vodafone Mobile Connect software or the built-in HP GOBI Connection Manager?
I have the 5310m, but no 3G connection. One thing you'll want to know before you purchase it is the spacebar is a little dodgy, you need to do some surgery on the laptop to make it work properly. This thread will explain what you need to do (basically remove the spacebar and add a little tape), other than that it's a great laptop.