So currently I have two PCs as I just got a new motherboard and cpu. One is running an Asus Z370-F with an 8700k and the other is running a Z390 Aorus master with a 9900k. We will call the Asus board system 1 and the aorus board system 2. I have SSD’s, both with windows on them. I have a 240 GB, drive 1, and a 1 TB, drive 2. Drive 2 has a version of windows on it I have been using for about a year now. Drive 1 has a pretty much fresh install of windows, though there are some important things on there. So let’s get into the problem. Whenever drive 1 is installed on its own into system 1, the system doesn’t go past bios. It goes past the logo, and then has a window similar to a cmd pop up with a slashing cursor and then into bios. I have tried using a windows iso to repair, but it found no problems. Whenever I plug drive 2 into system 2, it boots fine. Whenever I plug drive 2 and drive 1 into system 1 or 2, I can boot both of the drives fine into windows. I have tried clearing cmos to fix this problem. I want to be able to boot drive 1 on its own on one of the systems, but I just can’t see how I can or why it won’t work without drive 2. Thanks for the help in advance!