We will install all Windows Hyper-V servers at C:\HyperV folder. Each virtual machine will have its separated sub folder. The sub folder name will be the virtual machine's host name. Here is an example C:\HyperV\TestVM. All information about this virtual machine will be under this folder (Disk file C:\HyperV\TestVM\TestVM.vhd, virtual machine configuration C:\HyperV\TestVM\Virtual Machines and snapshots C:\HyperV\TestVM\SnapShots).
Step by Step Guide
1) Change the default Hyper-V folders
Please see How To Change Windows Hyper-V Default Folders to Store Hard Disk File and Virtual Machine Configuration File?.
2) Create Physical Folder Manually
You need to create a physical folder to store the hard disk file and configuration files first. It is C:\HyperV\TestVM or what ever you want.
3) Open Windows Hyper-V Manager
Windows Server 2008 Start > Programs > Administrative Tools > Hyper-V Manager.
4) New Virtual Machine
Click New > Virtual Machine in the right side Actions panel.
5) Specify Name and Location
Put TestVM as name and check on Store the virtual machine in a different location but leave C:\HyperV as it is. Then click Next >.
6) Assign Memory
Specify the amount of memory to allocate to this virtual machine. You can specify an amount from 8MB through the maximum physical memory. Then click Next >.
7) Configure Networking
Choose External Virtual Network from the dropdown list. If it is not in the list, you need to create the virtual network first. Then click Next >.
8) Create Virtual Hard Disk
Leave the name and location as default. Specify the hard disk size (25GB) based on your requirement. Then click Next >.
9) Option to Defer Installaling Operating System
Choose the default Install an operating system later. Then click Next >.
10) Review and Confirm
Review the configuration information. Click Finish button if everything looks OK.
11) Check the file structure
The file structure should be similar with below. Now you are ready to load operating system to your Hyper-V server. Please see Step by Step Guide to Install Windows Hyper-V Guest Operating System.