[arch-general] Dual boot issue, windows doesn't show up on grub

Hello , I installed arch on my laptop which has 2 hard drives , one is ssd (linux is installed there, also grub), one is HDD(with windows). So, at boot time , I can select either hard disk or ssd and can get either windows or arch. Is there a way for grub to see both Linux and Windows? I tried sudo update-grub and sudo grub-mkconfig -o /boot/grub/grub.cfg but they don't recognize windows. My windows is not uefi if that's any issue. My linux is on /dev/sdb2 and windows on /dev/sda2 if that's any concern. Thanks J