I already know that this can be done on Linux, One can boot to a flash drive that is write protected. Live modify folders can be symlinked to to a swap partition, and this prevents viruses from being stored between reboots. All file storage would be temporary until next reboot, documents could be uploaded to an online service.
My question is about Windows. There are times in our business when it will be necessary to use Windows in order to recreate what is seen by our customers. Short of operating in a Windows VM:
Is there a way to always be booted to a clean state on every boot?
Or, if this can only be accomplished with a large delay on boot
Is there a way to copy the entire OS to an external (flash) drive, with the ability to boot the the drive and reinstall the image on demand?
Other suggestions would be appreciated. (Perhaps a Virtualization server?)