asus b450 m-a ii

Ryzen 7 5700g Asus B450MA-II ASRock RX6600 Challenger 8gb 32 gb Corsair vengeance RGB 3200 4x8gb 1000w power supply Apevia? 256gb m.2 2th hdd 14tb external HDD Cooler Master Case Aio 240mm thermaltake I built this pc for my photographer fiance and it seems to seriously bog to the point where...

New Asus b450m-a ii and cpu and ram. The hard-drive and gpu are from an older system. The only way it will turn on is to jump the power pins on the board. Get a message to insert a boot disc. It runs and ends up at "Free dos" and a c:\> prompt. I do not know what to do. The old hard drive...