Check the hidden comments, as it contains a tidbit about Windows 7 becoming unresponsive if the USB drive has the same ID as the disk Windows 7 is installed on and how to fix it if it does.
You might try removing any extra USB drivers you have installed. (Especially the NEC drivers if you've still got them in there.) Also is that hook from your previous mail still active? If it is, you can try creating a new VM and attach the existing disk to it. (So you won't have to reinstall Win7 again.) That should give it a default config.
If all else fails, you may need to reinstall Win7 under a new VM profile to get it working again.
On Mon, 2022-06-06 at 09:51 +0000, firstname.lastname@example.org wrote:
It's observed that win7 guest will become no response if i eject usb storage "Eject MiniKing"
the last screen after i clicked "Eject MingKing":
After that, i have to hard reset the guest.