Prolific USB-Serial Sharing with Win7VM stopped working

Discussions about using Windows guests in VirtualBox.
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Daveyk021
Posts: 27
Joined: 7. Mar 2020, 07:44

Prolific USB-Serial Sharing with Win7VM stopped working

Post by Daveyk021 »

Hello there,

Things had been working okay. Last night I set the computer (Windows 11 Machine) so it would be read this morning and it worked perfect along with the Win7 VM. This morning, Windows 7 can not see the Prolific (Shared USB resource) device. In the Windows 11 Host, the USB to Serial adaptor works fine and can talk to the serial device. In the VM, it doesn't even see the port, as it did last night.

The WIN11 Computer did not do any updates this morning when I booted it.

I still can not share working REAL serial ports, to which this machine has five. The VM Win 7 machine see them, they just do not work. The prolific USB-Serial (new version) was the only one that ever worked. Not it does not. I update the VM7.0 to the latest 7.0.4, and as far as I can tell the VM Guest Addition updated to 7.02. I still have no idea how to get the latest of those. I think the VM7 machine gets them automatically and can show up in the CD icon and you run them. I ran 7.0.2 this morning and they installed fine. I still can not see the USB Serial Port as COM1 or any port as I di perfectly last night.

This is very frustrating. Why the sharing of the real Serial Ports do not work, I do not know.
Daveyk021
Posts: 27
Joined: 7. Mar 2020, 07:44

Re: Prolific USB-Serial Sharing with Win7VM stopped working

Post by Daveyk021 »

P.S. - Here is the error message when I try attaching it from the USB plug in the VM Machine.
Attachments
USB Failure.png
USB Failure.png (24.01 KiB) Viewed 2722 times
scottgus1
Site Moderator
Posts: 20965
Joined: 30. Dec 2009, 20:14
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows, Linux

Re: Prolific USB-Serial Sharing with Win7VM stopped working

Post by scottgus1 »

Carefully go through USB basics and troubleshooting. If you finish all the steps 1-7 and cannot get your USB device into the guest OS, carefully post the outputs of the commands in step 8 as text, not screenshots. Zip and post the logs step 8 call for, using the forum's Upload Attachment tab.

Also see
How to: Add a Serial Port in Windows XP and 7 Guest
Daveyk021
Posts: 27
Joined: 7. Mar 2020, 07:44

Re: Prolific USB-Serial Sharing with Win7VM stopped working

Post by Daveyk021 »

"If on Windows host, check that the VirtualBox USB Driver is installed in your host. Make sure your host didn't silently reject non-MS drivers (Google for Driver Signature Enforcement). Usually a re-installation of VirtualBox with the "right-click on the installer & Run-as-Administrator" trick, fixes this."

If I re-install VB, what about the Windows 7 VM that currently exists? I had to blow a Windows 7 license after a few days as it needed activated. So if I re-install VB, can I continue to use the current Windows 7 VM?

The USB Device btw is NOT is use by the host. In fact it disappears from the host device manage while the Windows 7 VM is loaded.
Daveyk021
Posts: 27
Joined: 7. Mar 2020, 07:44

Re: Prolific USB-Serial Sharing with Win7VM stopped working

Post by Daveyk021 »

scottgus1 wrote:Carefully go through USB basics and troubleshooting. If you finish all the steps 1-7 and cannot get your USB device into the guest OS, carefully post the outputs of the commands in step 8 as text, not screenshots. Zip and post the logs step 8 call for, using the forum's Upload Attachment tab.

Also see
How to: Add a Serial Port in Windows XP and 7 Guest
I edited the Windows 11 registry and found the USB sections as described in the trouble-shooting. Didn't help as there was no filters. So I did find some lines in the class section devoted to Oracle VB. I deleted two or three oracle lines in the VB section. I was desperate. Rebooted Windows 11, and then booted the Windows 7 VM. Wala, the com port was back in Windows 7 and working.

Why are these fxcking puters so difficult at times? LOL

I hope I remember this fix when it breaks again tomorrow.

I just wished real serial port sharing worked. It would be so much easier. As I figured out in the past, as soon as the VM load, all handshaking lines go low (I think that was it, not high) and it can transmit, but not receive. I tried it again with this VM update, still the same thing. I tried it with two PCI boards and the port on the mommy board; same thing.

Anyway, the USB to Serial port is working again. I hope more than "barely". The trouble-shooting guide did NOT have the answer but pointed me in the correct direction, which I guess, is an answer.

Thank you for pointing me towards it!!
scottgus1
Site Moderator
Posts: 20965
Joined: 30. Dec 2009, 20:14
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows, Linux

Re: Prolific USB-Serial Sharing with Win7VM stopped working

Post by scottgus1 »

Daveyk021 wrote:I edited the Windows 11 registry and found the USB sections as described in the trouble-shooting.
Neither of the posted tutorials mentions the Windows registry, as best as I can search, let alone editing anything in it. What did you do, and where did you read to do it?
Daveyk021
Posts: 27
Joined: 7. Mar 2020, 07:44

Re: Prolific USB-Serial Sharing with Win7VM stopped working

Post by Daveyk021 »

https://www.faqforge.com/windows/remove ... windows-7/

That is a link on the USB trouble-shooting page.
scottgus1
Site Moderator
Posts: 20965
Joined: 30. Dec 2009, 20:14
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows, Linux

Re: Prolific USB-Serial Sharing with Win7VM stopped working

Post by scottgus1 »

Thanks! I've never read that link before.
Daveyk021
Posts: 27
Joined: 7. Mar 2020, 07:44

Re: Prolific USB-Serial Sharing with Win7VM stopped working

Post by Daveyk021 »

YW, well, but it is still damn finicky. This morning, I spent 15 mins trying to get the USB to Serial working in the Windows 7 VM. It saw no ports. I checked the Windows 11 Host registry, and no oracle in the USB section to delete. The Windows 11 Host was really not that up very long. Exited everything. Rebooted the Windows 11 Host, re-loaded the Windows 7 VM and it had the port again and would work with the two day older than dirt software that I needed to run.

I really could not tell you what I did to fix it other than re-booting the host.

I wish the hell the software engineers would fit the real serial port sharing. I completely documented what happens to all the control lines in one post or more. The problem most likely is that no-one gives two hoots about RS232 communications anymore.

I've not really tried another VM as this one shows so much damn progress and I already blew my last Windows 7 Pro 32 bit license on this VM (it insisted on being activated and at the time it worked!!! Yea, I could run that two day older than dirt software that I needed.

I need to decode the serial port for this particular program, using my Siglent scope, to see what command the program is using to trigger a screen dump from the instrument under test and see if I can receive it. I can do screen dumps from various Tek Scopes in VB6 very successfully, I just need to worked with these old Industrial UT instruments to do the same and then not to have to worry about running the VM. BUT that will take a lot of time I really do not have - lol.
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