Ejecting a CD which is in use on a Windows VM may result in disappearance of the CDROM device.
1. Insert an iso.
It seems easier to reproduce the issue with an iso that contains large files. Here I use the LiveDVD from Fedora Workstation. The major content in the iso is a squashfs archive.
2. Copy the whole CD to C: partition.
3. When the dialog shows the current file being copied is the large squashfs archive. Then eject the CD. The copying then paused for a while. And finally an error message dialog is shown. The error code is 0x80070037. And then push "Cancel" (取消)。
4. Then the copying is stopped. And then open the Explorer, the CD device disappeared.
5. And then if any iso is inserted. The CD driver will not show up, either.