There is another way to install Server 2008 R2 on a VHD,which can be shorter or longer,depending on what you have.
This is a way on how to apply a WIM image on a partition.
What you need:
Windows AIK (Windows Automated Installation Kit)
If you have installed WAIK,select from its folder in the Start Menu command prompt for developing tools with administrator privileges. Connect the VHD using Disk Management. If you downloaded the evaluation from the Microsoft site,want to install Standard and burned it to a DVD or have a DVD,type in the prompt without quotes:"imagex /Info e:\sources\install.wim". Assume that you have the evaluation. You will see some indexes like 1,2,3,4,5,6,7 and 8. These are different versions which you can install. If you downloaded the evaluation,indexes match the following versions:
1 Standard Full
2 Standard Server Core
3 Enterprise Full
4 Enterprise Server Core
5 Datacenter Full
6 Datacenter Server Core
7 Web Server Full
8 Web Server <Server Core>
If your VHD has the letter G:,type this (if your DVD drive letter is different than E:\,choose the correct one): "imagex /apply e:\sources\install.wim 1 g:\". This will apply index 1 of install.wim,so you will install Standard Full. If you want another version,type something different like:
"imagex /apply e:\sources\install.wim 2 g:\"
"imagex /apply e:\sources\install.wim 3 g:\"
After applying the image file,you need to create boot files. Go to Start,then type cmd,right click and choose "Run as administrator". Type "bcdboot g:\windows".It will say that boot files were created successfully. To continue installation,reboot and select Windows Server 2008 R2. It will bring you to the last steps,where you need to select country,time and currency format and language input. It will restart again.
Of course,you don't need a Server OS if you use it like everyone who wants it for music,videos,pictures and surfing the Internet.Use it if you are a developer and the rest.Server OSes are not targeted to the common user,just the experienced one. That's why Media Center is not there.
Hope this helps and shortens your waiting time to finish installation.