> Since I do not have networking sorted out yet I cannot update win7 pro, and > it might be the updates which are needed for allowing more than two cpus.
hm, brief search on my side resulted in this tip: https://answers.microsoft.com/en-us/windows/forum/windows_7-hardware/windows-7-professional-x64-only-showing-2-of-8/0155f525-df73-4642-a828-21b80d1564b0 ---------- Some recommendations (in Windows, make sure you are running as Administrator): - Run MSConfig -> Change to Boot tab -> Advanced Options -> "Number of Processors", make sure there is no check mark. - Delete processor entries listed in Device Manager, then reboot. ------------- (I don't think BIOS options from this answer really apply directly to qemu case) also, if win (or some applications inside it) keep crashing with -cpu host, you can try to reload host (Linux) kvm module with additional option: "options kvm ignore_msrs=1" line (without quotes) should be added to /etc/modprobe.d/kvm.conf from https://www.passmark.com/forum/performancetest/4748-startup-error-number-4-on-qemu-bsod
