Steve Kroop <<info>>
writes:

The problem is Windows 8 and Windows 10. Starting with Windows 8,
Microsoft invalidated the driver for the USB chipset found in older
6015/20/30/40. There is nothing wrong with the driver, they just invalidated it.
The following link is for an unrelated product but the workaround resolves the
issue with the USB connection in Windows 8 and 10.

http://www.totalcardiagnostics.com/support/Knowledgebase/Article/View/92/20/prolific-usb-to-serial-fix-official-solution-to-code-10-error

Please note: install the fix with the instrument connected to your PC. After the
fix is installed, download the your instrument using the same USB port that was
used when installing the fix.

Here is the key found on the web site:

Windows 64-bit Fix:

Steps:

1. Download and save the "PL2303_64bit_ Installer.exe" by clicking
here.

2. Unplug all USB-To-Serial adapters from your computer - and double-click on
"PL2303_64bit_Installer.exe"

3. When it prompts you, plug in one (1) of your USB-To-Serial adapters and click
"Continue".

4. Reboot your computer. That's it!

Windows 32-bit Fix:

1. Download and Save the "PL-2303_Driver_ Installer.exe" by clicking
here.

2. Run the installer program. If it offers a choice to remove the driver, then
select to remove the current "bad" driver.

Then run the installer again to install the correct driver.