This question involves partitioning as well as grub. As it is years since I installed windows, I can't remember if its installer will recognize and more importantly, leave alone, Linux partitions. My guess is that it will probably just overwrite them. In this case you may have to make some free space on your disk to install Windows into. Gparted is the tool for this which you can run from the MInt installation disk.
Once you have created new partitions to put Windows on then you can install Windows to those partitions only (so you don't overwrite Linux). When that is done, as you rightly say you won't be able to boot LInux any more. There are two possible solutions to this. To my mind the first is the best one. Follow the instructions here to install and run boot-repair into your live Mint session and use it to repair grub (ie boot from the live dvd/usb, whatever you have):https://help.ubuntu.com/community/Boot-Repair
The second option is to install EasyBCD into windows and then use it to detect and boot your mint partition.http://neosmart.net/EasyBCD/
(that site has a lot of 'buy now' buttons all over it, but I promise you there is a free version for non-commercial use, you just have to search around for it). It has some very good documentation too.
A third option would be to install Windows letting it take over everything and then install Linux again (alongside windows) which will take care of both partitioning and installing grub but of course you will lose any modifications you have already made to your Mint installation.
Fujitsu Lifebook AH532 Laptop. Intel i5 processor, 6Gb ram, Intel HD3000 graphics, Intel Audio/wifi. Realtek RTL8111/8168B Ethernet.Ubuntu12.10 (Unity), Mint14 (Cinnamon), Manjaro (Xfce).