FWIW I'm using Virtual Machine Manager, QEMU/KVM for Linux guests, but VirtualBox for Windows guests. Since IIRC around a year ago my Windows 7 (64-bit) guest doesn't work anymore. I tried to restore it from a backup, not just from a snapshot several times, without success. I can't comment on my Windows XP (32-bit) guest, but my Windows 10 and Windows 11 guests (both 64-bit) are still working. My Windows 11 guests doesn't shut down, but a sudo pkill VirtualBoxVM doesn't harm. IOW I'm using Windows 10 and Windows 11 regularly, but stopped using Windows 7 a long time ago. I don't care so much because I don't really need Window 7, but it's still a nuisance. Windows 10 and 11 are important to me and XP could also be important at some point. Fortunately, Windows 7 has become unimportant to me, so I've never really bothered about it. I don't no if this is on-topic, I just want to mention that Windows 7 is also broken on my Arch Linux VirtualBox host.