You can get windows back on the bootloader like this:
go to Yast → System → Boot Loader. The Grub configuration screen comes up with the Tab “Section Management” activated. In the lower right is a drop-down selector labelled “Other”. Select from “Other” the option “Propose New Configuration” and then wait for Grub to analyse your partitions and display a new configuration. This may take a while. Important: When that finishes, activate the tab labelled “Boot Loader Installation” and select to “Boot from the Master Boot Record”. [Yast will often default to booting from the root or boot partition rather than from the MBR but that’s for experts only – always choose the MBR.] Then click Finish to save the changes and install the reconfigured Grub into the hard drive’s MBR. If you get a message that "The bootloader boot sector will be written to a floppy disk … don’t bother with the floppy – just click OK to proceed and install to the MBR.