Hyper-V lives in US ! AKA Virtual Machine Management Service entered stopped state.

Imagine you decided to upgrade to Windows 2008 Server and want to try it's new sexy Hyper-V hypervisor. Imagine also that you appear not to live in America (USA) and you set your locale settings to something different than EN-US.
Guess what!
You will never make Hyper-V running! You end up with:

Virtual Machine Management Service (vmms) failed to start.

or

Virtual Machine Management Service entered stopped state.

Period.
No additional info.
No related entries in the event log.
OK. Now what ?
You will go for:

My CPU DOES support Virtualization (double checking with manufacturer web site and BIOS settings).
I aslo made sure that the No Execution bit or DEP is set to enable from the BIOS.
I also went for latest updates from windows update.
What am I doing wrong ?

Well. The point is that you are not doing wrong. but Microsoft is doing wrong. You will google the problem, and may you will find this thread, or that post. And you will realize that you now must (you must not reinstall the Server OS!):

1. Remove (uninstall) the Hyper-V role.
2. Set locale settings to EN-US
3. Set location to USA
4. Force locale settings to be applied to all system accounts
5. Restart
6. Install the Hyper-V role
7. Restart
8. Go and create your virtual machines

Come on! Do we really need to do this ? And what if I change back the locale settings? Well I still do not know what will happen if I do this, but I am going to check in the next couple of hours or days. So stay tuned for updates!

P.S. And NO, this is not because I am with pre-release beta of HyperV. My Version is: 6.0.6001.18125 !

Cheers!