Windows CDs don't contain DOS, as such. They do contain something called the Recovery Console, but I'm not sure that it would be suitable for what you want to do.
GParted Live is an ISO file that you make a bootable CD from (Google it and have a look at the web site). You boot from this CD and it doesn't depend upon any OS being present on the hard drive. You can use it to do various partitioning and formatting tasks. There are similar commercial offerings, e.g. Partition Magic or Paragon Disk Manager, but GParted is Open Source and is free.