USB to Parallel on Windows 10 and Windows 11

[PaulSP]

This is just a note on something I learned on my HP Envy with Windows 10 which also applies to Windows 11 on a different computer.

I have a USB-to-parallel adapter, and it does not show up as such in the Ports list.

Instead, a USB001 port shows up. The convertor is listed as well, but choosing it did not work.

On the HP, I had another printer, one that connected using USB (no converter). I also had a USB002 port.

Sometimes Windows 10 would decide, on its own that USB001 was connected to the USB printer and USB002 was connected to the LPT printer. This, of course, did not work until I switched the ports.

My Windows 11 setup is much simpler: only the LPT printer exists. For the first month or so, USB001 was the only USB port available, and it worked.  I do not use the printer very often, but at some point during August it stopped working. I had other things to investigate, so I didn't get around to investigating it until today.

What I found was that Windows 11 had, at some point, created a USB002 port and decided that the printer had to be connected to it. Changing the port fixed the problem. So far as I can tell, it did this all on its lonesome, with no input or encouragement from me.

The points here are:

1. The device itself may not show up or be useable, but a USB00n printer port may be available that will work.

2. If the printer suddenly stops working, check the Ports and see if a new USB00n port has suddenly appeared.

Do not be surprised if the port you have been using is labeled "Virtual printer port for USB" and the new one -- the one that works -- is labeled "UnknownPrinter". Or if they "flip back", as it were, at some point in the future. Or if the device now shows up as "Unspecified" with very little information.

Just be happy that the printer you want to use is still useable.

[Kuroi_Kenshi]

Hi @PaulSP,

Welcome to the HP Support Community!

Thanks for reaching out!

We're thrilled to have the opportunity to assist you and provide a solution.

I understand you’re noting your experience with USB-to-parallel adapters on Windows 10 and 11 and how port assignments can affect printer functionality. Here’s a concise summary and key tips based on your observations:

USB-to-Parallel Adapters Use Virtual Ports

The adapter itself may not appear as a traditional LPT port.

Instead, Windows assigns a USB00n virtual port (USB001, USB002, etc.) that the printer communicates through.

Port Conflicts Can Happen

If multiple USB printers or adapters are used, Windows may reassign ports automatically.

For example, USB001 may initially work, but after some time, Windows could assign the printer to USB002.

Check Ports if the Printer Stops Working

Open Devices and Printers → Printer Properties → Ports.

Look for the USB00n ports and switch the printer to a different one if needed.

Sometimes the working port may show as “Unknown Printer” or “Unspecified”, this is normal.

Port Flipping Can Recur

Windows may flip USB virtual ports after system updates, reboots, or connecting other USB devices.

If your printer stops responding, always check for a new USB00n port.

Don’t Worry About Labels

The labels (“Virtual printer port for USB,” “Unknown Printer,” etc.) aren’t always meaningful.

Focus on which USB00n port actually prints correctly, that’s what matters.

I hope this helps.

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