If you use Microsoft Virtual PC and are still trying to find an easy way of making ISO images to put files onto your virtual drives then I have a treat. If you want to use some free burning tools instead of the standard retail bloatware that is CD Creator or Nero then I have a treat for you also.
DeepBurner offers a free version of their software and it is very good. Very lean, burning side works well, allows you to create custom autorun menus, bootable disks and creates ISO images. The pro version has a couple of extra buts, but the meat of it all is in the free version. Been using it for a couple of weeks and I am loving this because it is so basic.