well you don't do it from linux at all, you'd reboot with the CD in the drive, so the existing operating system is not relevant.
Note that adding windows to an existing Linux system can be very difficult, as Windows is so thoughtless about how to configure itself, how well it understands other filesystems and such. You'd want to shrink down the partitions already in use by Linux to allow Windows to have a space to install into, so you need to check if this is even possible in the first place.
Windows will also destroy your MBR, meaning after installation it will be impossible to boot anything other than windows until you reinstall the Grub bootloader and add in the relevant windows config (it is possible to do a similar thing for the windows boot loader, but it kinda sucks)
The recommendation from this mess is generally to install windows first and just leave space for Linux, and the Linux installer will happily do the clever stuff to make the system dual boot.
Mind you, if you just want to REPLACE Linux then just stick the windows CD in and reboot and let it destroy everything.