I used the following steps to install Ubuntu (10.10) version in the my Windows Server 2008 R2 Hyper-V machine.
1) Created a new Hyper-V machine
2) Downloaded the latest Ubuntu ISO. You can notice few options on this page:
(a) Download Desktop Edition – I used this.
(b) Burn your CD or create a USB drive
(c) You can try it before you install it
3) Create a legacy Network driver and associate it with the above Hyper-V machine
4) Select the Ubuntu ISO by the following option: Hyper-V –> Media –> DVD Drive –> Insert Disk
5) Started the Ubuntu Hyper-V and mount with above ISO
6) Select the options to Install Ubuntu and its configuration. For the disk management, you can use the entire drive or customize the drive partition as per your requirement.
One it’s installed, it will request you to restart. During the time, make sure to remove the above mounted ISO drive.
I would rate the installation is pretty straight, works fine with all the drivers. I haven’t faced any glitches during the above work and loads with 640 * 480 display configuration.