when i first tried hyper-v i couldnt get it working. i installed the role , rebooted the server and in server manager i saw hyper-v service not available. looking in services.msc i saw that the virtual machine service was not running, trying to start it gave an error with incorrect parameter. after googeling a lot i found a solution at http://www.servercare.nl/Lists/Posts/Post.aspx?ID=17. 

below i made a short summary to fix the problem.

First remove Hyper-V, if you have it still installed, and reboot.

 

Now go to the Regional and Language options in the control panel. And follow the settings as shown below.

 

Go to the next tab: "Keyboards and Languages" and select "Change keyboards"

Make sure this only shows the US keyboard. Note that you can't remove a keyboard when it is selected as Default input language, which of course makes sense.

 

Change the system locale:

 

 

And then –make sure not to forget this-! Click the button "Copy to reserved accounts…". This effectively wipes out the old settings (otherwise you have only changed it for only the account you were working under, and Hyper-V does not like that).

 

Now start the Server manager and add the Hyper-V role, reboot… And with a little luck you have resolved the issue. As you can see from the below picture; everything is running fine now!