chrisfromgreece This pc i have temporarily can't boot netbsd , i tried with legacy, i tried using uefi nothing makes the disk bootable !
sysinst installed files onto this disk, then it shouldn't be difficult to make it bootable. Can you boot the USB-installer, drop into the command-line and post the output of these commands (even a picture of the screen will do):
fdisk /dev/wd0 # or ld0 (1st NVME); sd0 (1st SCSI disk); wd1 (2nd ATA disk), etc.
gpt show wd0