Enabling Hyper-V on Dell XPS Laptop
Now that Hyper-V is RTM (download update here) I figured I'd take the plunge and dual boot my laptop by installing a Windows 2008 x64 partition. All went well and I installed the Hyper-V role and the RTM update. When it came to starting up a VM however I found that it wouldn't start because the Intel-VT extensions were not enabled (they are Off by default). After quite a few scans through the BIOS settings I finally found the correct option (it's under POST Behavior which to me seems to be not very intuitive!). The instructions for enabling the required hardware settings for Hyper-V are below (Dell XPS M1730 with A06 BIOS)
Hope this helps, it took me a while to find this and searching google didn't help (in fact most of the dell forum posts seemed to indicate it required a BIOS update past A06 or wasn't possible).