I just received this error message while trying to install Microsoft Hyper-V Server 2012:
We couldn’t create a new partition or locate an existing one. For more information, see the Setup log files.
Sadly, Microsoft don't tell us here where and how we can find this log files, so I do.
First of all you need a command prompt, press "Shift+F10" to open one.
Now type in "notepad X:\Windows\panther\setupact.log" and you have it:
In my case the hard drive was simply to small