pc wont boot after

I built my pc today and i receive a bios message that the pc has POSTed in safe mode Press f1 to run setup and i cant bypass this loop What can i do? I have an i5 10400f Asus b460 m 8gb 2666mhz ddr4

Yesterday i took my pc apart cleaned the dust reapplied thermal paste to both the cpu and gpu,(GTX 750 1gb ASUS) put everything back togheter and my pc would not signal beep codes and monitor shows no signal. I tried a old 9800GT and the pc booted normally i tried the 750 on another computer and...

I’ve just bought a new m.2 sad for strictly storage not a boot drive, as soon as I plug it in my pc won’t be and is stuck on automatic repair loop, so I unplugged the ssd and it started booting right up like normal, even while the ssd was plugged in I made sure the boot drive was the same drive...