Clonezilla has worked great for me in the past. It's pretty easy to install to a usb and then write the disk image to another usb drive as long as you aren't using raid on the OS. A 32gb usb stick ought to be able to hold an image of a fresh install of windows with all the apps installed that you'd want in case of a crash. Of course you can write the disk image to any other media other than the drive you are imaging. The clonezilla usb drive only needs to be about 200 mb in size.

Tuxboot will set up the bootable usb drive automatically with updated clonezilla.