First you need the Bits get them here :
The Windows Developer Preview is a pre-beta version of Windows 8 for developers. These downloads include prerelease software that may change without notice. The software is provided as is, and you bear the risk of using it. It may not be stable, operate correctly or work the way the final version of the software will. It should not be used in a production environment. The features and functionality in the prerelease software may not appear in the final version. Some product features and functionality may require advanced or additional hardware, or installation of other software.
Now that we have the bits you can start run this in windows 7 and boot from VHD.
First open the Hyper-V manager and create a new VM
and Finish the VM. Press start in the management console.
Open the VM the PE loading is really fast I do the Next next Finish install.
Well it starts with a green screen ??? you have to flip the screen , no touchscreen use your mouse or go to the left end of the screen the desktop pops up.
There is no need to install the Hyper-v Options it is already included.
changed installed options and disable the tablet options just like windows 7 Control panel etc.
After the reboot below is the bootup screen.
slide with mouse and there is the logon screen and it opens with the start menu.
The build in IE is version 10 .
Really Nice is the Windows Repair & recover
Windows 8 Recovery boot from ISO or USB or use an older media thing.
Choose the troubleshoot option. Now there are two options Refresh your PC or Reset your PC
The refresh replaces the Windows Files and leaves the Personal files alone.
The Reset will remove all apps and personal stuff and returns windows 8 in the default mode.
This option is really nice, it save reinstalling the apps , Will this also work on the server version. cool trick for RDS servers.