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Using A: as drive letter for DVD drive?

In a moment of wild abandon, I thought I might use A: for my DVD drive, since it has taken over the functions of the ancient floppies originally assumed to be in A: and B:.

Apps that normally operate with DVD and CD drives do find the media correctly on A:, but DOpus doesn't. It sees the device, and adds it to the folder tree, but it insists there's never any media present, whether formatted as a music CD or a data CDROM.

I'm guessing the BIOS or the OS may be hard-wired to make certain assumptions about what COULD be in drive A: or B:, but I thought I'd check, in case there's something in DOpus that would make this unconventional drive assignment possible.

Thanks in advance,


The drive letter should not matter, at least as far as Opus is concerned.

The information about what is in the drive comes from the operating system.

Some DVD drives/drivers do not correctly send media change events, which will affect most applications if you have a drive with that issue. They won't know when media has been inserted or ejected, but should still be able to access the drive if you explicitly navigate to it.

File Explorer does something extra to detect when the media state is wrong due to a device not notifying the OS properly of insertion/ejection. If you look at the drive using File Explorer, and it notices the state was different to expected, Explorer will then broadcast that information to all other software. If you find it works in Opus (or something else) after looking at the drive using File Explorer, that's probably the issue.

Running dopus.exe elevated can also cause problems due to that blocking the messages about media insertion from reaching the elevated process.

Thanks, Leo.

It turned out to be One of Those Things. I've had A: assigned to the DVD drive for a week or so, and only just started trying to use it. Media changes seemed to be registering, because Opus immediately showed the drive in the folder tree, and removed it when I removed the media. But Opus could never display any disc contents.

I had rebooted and reassigned the DVD to M:, and Opus worked correctly, seeing the contents. When I reassigned it to A: again, and rebooted, now all is working. Perhaps Win10 healed itself, or perhaps the original assignment to A: happened before some mysterious MS update, and needed to be reassigned to A: anew. Heaven knows.

IAC, it works just like any other drive letter. Because of the ancient history of A:, I feared there might be some weirdness assigned to it, but it looks like the only residual influence of the floppy disc era is the assumption that the first hard drive is C:.

I often tell people that if Windows is working strangely, rebooting, more than once or twice, can often work small miracles.


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A and B used to be reserved for diskettes and floppies respectiveley.
Even if that rule no longer applies, there may still be the possibility of problems trying to use it for other purposes.