I can't install Windows Server 2008 R2 X64 edition on Windows Server 2008 Hyper-V. I would like to know X64 version can run on Hyper-V or not.
If you already have the Hyper-V Role installed and are having trouble in installing Windows 2008 R2, then try using another ISO image or provide the error message you are getting.
windows 2008 R2 is a 64 Bit ONLY Operating System
If you are running windows 2008, make sure your host operating system is 64BIT and that Hyper-V is configured.
A good thing would be to update your server to the latest service pack (if you have a x64 box and OS).
then try to install again.
Microsoft has a list of the supported guests: Virtualization with Hyper-V: Supported Guest Operating Systems