During the football games today, I decided to run some dual booting experiments using a ThinkPad T430s, Windows 7 Ultimate x64, and Windows 8 Pro x64. In the ThinkPad is a 320GB HDD.
On the initial test, I decided to split the hard drive right up the middle and create two partitions. One for Windows 7 and one for Windows 8. Conventional wisdom has always advised to install the most recent operating system last and I did just that.
The Windows 7 install proceeded without issue. Once I had verified that was operational, I popped the Windows 8 DVD into the machine and booted from it. Windows 8 installed without issue and everytime the machine is booted, you are presented with a menu so the OS can be selected. Since Windows 8 is the default, you can just let it boot or select Windows 7.
People have been booting from multiple partitions for years. There’s just one problem, how do you take a partition and move it to another HDD or SSD and machine, then re-use it? It isn’t easily done though tools like Acronis True Image Home 2013 certainly make backup and recovery easier these days.
Boot From VHD
When Windows 7 came out, there was a new technology called “native boot from VHD”. For the uninitiated, VHD stands for virtual hard disk. Native boot from VHD allows you to store the OS, apps and data inside a single VHD file. By installing the OS into the VHD, it is rather easy to backup via a file copy, and of course move and use on another storage device.
Back in May of 2009, I spent a considerable amount of time documenting how to implement boot from VHD. See the blog post at http://blogs.technet.com/b/keithcombs/archive/2009/05/22/dual-boot-from-vhd-using-windows-7-and-windows-server-2008-r2.aspx for that work.
Today I decided to see if the same techniques and commands would work with a Windows 7 and Windows 8 implementation. I am happy to say the instructions worked very nicely. The resulting Windows 7 VHD file was 7GB. The resulting Windows 8 VHD file was 8GB. Coincidence? LOL