I am actually screwed. After heavily using Windows 7 RC on a VHD for a couple of months now, I am at a point where I need to dump it completely if I want to upgrade it to RTM. I was totally stupid that I was only hoping the upgrade path from RC to RTM is available without noting this import statement.
If you boot from a VHD, you cannot upgrade the Windows Version in the VHD to a newer version.
Bam, I was hit, pretty hardly that I had to go through all the installation process again to get a working system on RTM version. So if you are like me, a native VHD boot lover and have been heavily relying on it so much for quite a bit time, you are as unfortunate as mine. We both have to live with it.
So before I move on with the VHD again, let’s review what’s not supported in this awesome native VHD boot feature in Windows 7:
# Using VHDs to native boot with previous versions of Windows. Windows Vista® and Windows Server 2008 (and previous versions of Windows) do not support native boot. Native boot VHD requires significant changes to the operating system and these changes are new in Windows 7.
# Hibernating to conserve power. An operating system that is booted from a VHD image does not support hibernation. Native boot is primarily targeted to Windows Server or managed desktops, and development and test computers where hibernation is not a critical feature.
# Using compressed or encrypted VHDs for native boot. VHDs that have been compressed by NTFS or encrypted using Encrypting File System on the host volume are not supported for native boot.
# Configuring native VHD boot if the host volume is protected by Bitlocker™. You can save a VHD file on a file system that is protected by BitLocker, but you cannot use the VHD for native boot or enable Bitlocker on the volume(s) that are contained inside a VHD.
# Booting to a VHD that is located on a remote share or a USB flash drive. Windows does not support booting to a remote share or a USB flash drive, whether installed on a physical volume or from a VHD. You can boot the Windows Preinstallation Environment (Windows PE) from a USB flash drive, which is supported for Windows deployment. Windows PE typically boots from either a Boot.wim or an installed image, but booting Windows PE from a VHD is not supported.
# Upgrading the operating system booted from a VHD. If you boot from a VHD, you cannot upgrade the Windows version in the VHD to a newer version.
Take look at Frequently Asked Questions: Virtual Hard Disks in Windows 7 for more details.