bios update help please !!

[mboyd18]

so i bought a msi x370 gaming pro carbon and a ryzen 5 2600 and need to do a bio update ( tried to put the cpu in and board lights up but black screens) so i put a ryzen 3 1200 and it gets me into bios and windows, however when i tried to update the bios the m flash recognizes the bios update on my USB drive but when i select it nothing happens only option it gives me is to exit and reboot ( tried that also didn't do anything as far as updating bios) I have obviously tried the web searching and YouTube route with no luck so far. wondering if there's anyone who has come across this issue before and knows how to solve it, T.I.A. i only have about 1 year experience building and messing around with PC's and have not come into this problem before so any help would be greatly appreciated. cheers.