Infinite Boot Loop No Bios

[KarsonB]

I downgraded my windows from a recent 10 version to an older one. I did this through as ISO and it was set to keep my apps and documents. After it got done, it restarted to finish, and every since has been stuck in an infinite boot loop. It turns on, and then after maybe 5 seconds, turns off. Then 3 seconds later turns back on. If I spam click DEL, then the PC wont shut down, but the display still turns on and off. I've been able to access the bios once out of maybe 30 tries. I unplugged every storage device, and it still infinitely boots without letting me into BIOS. Cleared CMOS. Flashed the bios. Moved RAM sticks into every configuration possible. No components are overheating. I really need this PC up and running ASAP, please provide any help you can.