How to delete "Unknown Disk 3"

I just booted Ubuntu Linux to see what it shows. I'm not a Linux expert but from what I see, only the 3 "real" drives are listed by Ubuntu. Not "USB Drive" as Windows 7/8.1 show.

Great! That tells us that it is not a real device, actually connected to the PC.

I would now feel more comfortable in pursuing the registry edit path.

I ran the suggested USB drive cleanup program, which is basically a registry program, and it didn't fix it.

If its a registry problem, both Windows 7 and Windows 8.1 are seeing the exact same thing.

In your case, I would just like to repeat what I had said in my post #21 after drive clean-up failed to correct the problem which makes it clear that it isn't a non-existing drive. It kicks up with Windows whether 7 or 8.1 or so it looks.

"OK, I wouldn't leave it to mystify me. The clue is that when you reboot it kicks in.

When time permits, enable the device and then perform a clean boot. Then step by step try to find out which service/ startup is trying to kick up the drive. May be you will find the culprit."

(Boozad's case looks different and is not comparable with your problem and so you can't draw lessons from each other )

EDIT: I also vaguely remember that in the past some motherboards came out with a bit of built-in solid state memory, to enable faster booting/smart caching or something like that. You can check your motherboard's documentation and specs for this feature. My only doubt is if it indeed had such memory that could show up as a fixed drive, you should have seen it from the beginning and not all of a sudden now.( Your ASROCK Z77 does seem to have this integrated SSD -Intel Smart Response Technology)

Run the DriveCleanup tool again. Then download the 32 or 64-bit version of DevManView as appropriate for your machine. Confirm Unknown Disk still showing in Disk Mgmt. Then run DevManView Ctl-A to select all items, Ctl-S to save. BE SURE to change the Save As type to Tab Delimited Text. Then save and upload the file

/* EDIT */

fireberd said:

Drive cleanup did not fix it. And nothing showing in Device Manager. The device is not present so nothing to show.

Confusing as some device and its driver (whether real or virtual) must be present if Windows keeps enumerating the device even after its been uninstalled

I assume you've checked the Disk devices. I'd also count the number of USB Mass Storage and USB Composite devices in DevManager under USB. Uninstall the device again. Then count those devices again to one of them have disappeared

I'm hesitant to run DriveCleanup tool again. It didn't fix or find it the first time and I was in panic mode when I tried to setup for a recording session that same day as my Roland Studio-Capture recording interface unit was missing and my bank of USB connected burner drives were also missing. I had to reinstall the Studio-Capture to get it going, the burner drives reinstalled when I powered them on.

Somewhere there is a "logical" explanation for the unknown USB Disk 3. If I were to do a clean reinstall it would take weeks to get my recording studio back working and I would have to do it to both Win 7 and Win 8.1.

I just ran the USB Device View from the same site that has the DevManView. There is nothing listed in the USB Dev View with any name even close to the Device Manger "USB Device" or any code listed for the device in the Properties Details panel. Or for the "Disk 3".

However, DevManView has he device listed and when linked to the Registry it shows the device.
Here is the DevManView for the device and the Registry listing

Could you please upload the DevManView report? (remember to Save As Tab Delimited Text)

/* EDIT */
Close DevMgr if open
Then Computer->Properties->Advanced . Add an Environment Variable: create new SYSTEM variable

Code:

devmgr_show_nonpresent_devices

set value = 1.
Open DevMgr. Click View->Show Hidden Devices

Open DevMgr. View->Device by Connection. Look for it again. Expand all items and have a look through all. (Especially look if any "virtual" sounding bus is listed among the devices.) This is may well be a virtual device which is one reason it isn't listed under USB or by USB View.

From your prior post, looks like you already know it will probably appear listed as simply USB Device

The device is shown in the Device Manager as USB Dev. Here is the screen shot of the Device Manager (I had posted this earlier in this thread).

Also the screenshot from the DevManView report is the device. I previously posted that screenshot and the listing in the registry.