Windows 7 and Windows 2008 R2 have a really useful feature called “VHD Boot”. With that you can boot your entire Windows out of a Virtual Hard Disk file (as those used with Virtual PC or Virtual Server).
This VHD file is mounted as a virtual disk, you can use it as a normal hard disk drive, but all the data is stored in ONE file. The machine is booted physically (unlike with Virtual PC), so you can only run one at a time, but have the full machine’s power.
The advantages are magnificent:
- Simply copy one file (the .VHD file) and you’re entire system is included.
- Create incremental VHD files: One VHD file can be based on another one. So if you have different systems, create a base Win7 VHD and make all others incremental. This will save a lot of disk space!
There’re also some small disadvantages 🙂
- The .VHD booted OS needs to be Windows 7, Windows Server 2008 R2 or later.
- There’s a performance decrease of about 3%.
- Hibernate and some BitLocker scenarios don’t work
(BitLocker CAN be used within the guest VHD though, but not on the disk where the VHD resides). - Windows Experience index won’t work.
So how do you install a VHD-Boot machine?