It seems that the imagex tool is only available as part of the Windows Automated Installation Kit (WAIK). For Windows 7 the kit is an ISO disc image available for download from Microsoft. The Website reports that the download size is 1 GB, though my download currently shows that the file is 1.7 GB.
While writing this post I’m in the process of downloading the disc image. At this point I don’t know exactly what I’ll need to do to get the file into an active Windows 7 installation, but I’m assuming I’ll be able to boot the Windows PE disc and then copy the imagex tool out.
My intention is to use this tool to backup an active Windows 7 system. The image will be stored on a drive attached to a Mac across the network.
It may be possible to find a site that offers only the imagex tool itself for download. However, I think downloading the file directly from Microsoft in its current packaging is probably the best method.
Update: The WAIK can be installed directly into a running system without having to boot into a Windows PE environment. However, imagex seemed to have an issue with creating an image on a network share. It’s likely that I was missing some steps or information. I ended up going the easy route and simply using the built-in Windows backup utility instead.