yes mobo serials can be easily modified, but not for all, you also have to flash your bios which is not that easy for other type of pc/laptops, some bios are locked and requires other types of unlocking tools such as spi programmer which is difficult and can only be done by computer experts.
i appreciate your response! thanks for that already done this steps, reinstall windows, changing serial id on hdd,ssd,mobo uuid, mac address, my problem is the bios which i really don't have any idea how to spoof it, i've tried restoring it to older versions but fails, also it doesn't update. and i ask some techies about it and they just said that my bios is locked. and hopefully if you have any idea/solution i would highly appreciate it.