Most computer motherboards have between two and four slots for RAM, and if one of these slots fails, your computer won't see the RAM stick installed in it. Testing your motherboard's RAM slots ...
Intersting, on Twiotter somebody posted a retail ASRock X670E Steel Legend motherboard, which has a sticker covering its four DDR5 DIMM slots. The sticker has some info on the ideal DIMM slot ...
Use the following suggestions if one RAM slot is not working on your Windows computer. The first thing you should do is check for physical damage. If your RAM slot(s) is damaged, it will not work.