USB should always work, so it is unclear why your unit works with one computer but not another. You could try going into Control Panel/Device Manager and uninstalling the driver, then replugging and try again. Don't try this if this is beyond your knowledge.

If the above does not work, there is probably some problem with your computer. You then have two options:

1) Try another USB cable and another computer.

2) Send your H9 in to be checked, but there is probably nothing wrong with it.

For unknown reasons, some Windows Bluetooth adaptors do not work with H9. See previous posts for suggestions of those that work.