SonnyNXiong :
If I get a new motherboard will i have to buy a new windows10 or is the windows10 linked to my storage? I don't have a disk neither usb for windows10.
Windows 10 is linked to your motherboard. If you want to make sure your license key is linked even after then you must connect your microsoft account within windows, then after you have installed the new motherboard, make sure the account is still linked and you should not have any issues.
If for some reason it does not link and it gives you the "Activate Windows" watermark on the bottom right simply go onto microsoft chat support and they will activate it for you for free. I did that just a few days ago and was surprised that they activated it for free for me.