How to import hyper-v module on Windows 2008 and 2008 R2

Hello

I'm installing in a lab 2 Hosts

1 host with Hyper-v 2008*

1 host with Hyper-v 2008 R2

i TRIED TO FOLLOW http://www.virtualizationadmin.com/articles-tutorials/microsoft-hyper-v-articles/storage-management/administer-microsoft-hyper-v-command-line-cli.html

BUT DID not work

What must I do to be able to use POwershell to manage my hyper-v architecture

Tks