so did you install the windows? do that firstAsRock Z390 Phantom Gaming ITX/ac;
9900K;
RTX 2080 Ti;
NVMe SSD;
Corsair 750W.
I've checked in BIOS everywhere but can't find and as I wrote in Windows installer I see it, in the menu where you have to choose drive to install OS. BIOS version is newest as I know.