Yes, it is possible to install Windows after Linux. However, expect to lose Lilo or Grub - Windows does not play well with others and will overwrite your mbr. Windows also prefers to be first on the disk and may well have problems after install.
If you really need to do it this way, keep your SuSE disk1 (or rescue floppy) to hand so you can reinstall your bootloader and have your Windows disks to hand in case it loses files that it needs.
Personally, as long as I hadn't tweaked or added or saved too much to SuSE, I'd pretend I never had it installed and do Windows first and SuSE second.
And, of course, Welcome to LQ