If they are truly identical, i.e. same hardware, etc., then possibly the easiest process is to install but do not register, Windows on a single machine - you can even install additional software, install your linux image & grub making a note of all of the patition details to get dual boot working.
Then boot that machine from a cloning tool such as CloneZilla or PartImage and create an image of that machines whole hard drive including all partitions on something like a USB hard drive tutorial here. On the other machines you will repeat the process but installing from the image. You may also need to use parted magic to recreate the partitions noted above. Once installation is complete you can boot into Windows and only then register the Windows installation - if you register Windows on the original machine the image will not work on other hardware.
Linux Live UDB Creator can help to create your bootable USB device including CloneZilla but I would recommend creating one based on CloneZilla-SysRescCD which will give you access to all of the tools that you might need or System Rescue CD alone if you are going to use PartImage.
You may well need to enter the BIOS on each of the machines to enable USB booting and may have to change a security setting to allow non-Microsoft signed software to boot.
Microsoft Deployment Toolkit, MDT, also allows you to create custom Windows installations and deploy them but unless you have a lot of machines to install I would recommend just using it to install a customised Windows and then add the Linux and Grub installation manually seperately. If you prepartition your hard drives than install Windows using a MDT generated image and follow on with installing Linux from a boot USB and setting up the Dual boot it is quite quick.
Note that, while it is tempting to use a DVD rather than a USB stick or USB hard drive, DVDs are much slower for reading information than USB 3 devices espeically memory based devices such as USB sticks or some USB drives.
One word of warning - If you are trying to install Windows 7 from USB 2/3 you will need to patch the Windows 7 install image using the MS toolkit both for the initial installer boot environment and for the image(s) that you are planning on installing. I know from bitter experience that later USB hardware is not supported to the level of not being able to use rather than not being able to take advantage of the full speed by the Win7 SP1 images.