David G. Miller wrote:
The problem with suggestions to just install Windows and then either use another boot loader or repair the grub installation is that you are stuck doing that work through Windows. My experience has been that Windows isn't as easy to work with for making changes to the boot loader and any approach that overwrites the Windows boot loader may leave you with Windows not being bootable.
You can always boot the centos install CD/DVD with "linux rescue" at the boot prompt - or use a knoppix or other live cd distribution. And it is a good idea to be prepared for this. I don't know if you want this, but it is also possible to set up VMware server with access to the raw device so besides dual booting you have the option of running the other OS as a VM guest. Most windows versions have to be re-licensed when they see different hardware even if it is virtual so you may have to use windows as the host for this if you do it often.