1. Plug-in the BC-337.
2. Go to your Device Manager. To access this, you can click the Start button and right-click on Computer. Select Manage > Computer Management > System Tools > Device Manager > Ports (COM & LPT).
3. If you see a virtual com port, right-click on it and choose Properties.
4. In the Properties window, select the Driver tab and click on Driver Details.
5. Look at the driver files and check out this system file: zteitserprt.sys
6. Take note of this file's location. Usually, it's located in this folder: C:\WINDOWS\system32\drivers
7. Go to that folder and search for the zteitserprt.sys file.
8. If you find other zte files, please rename all their extensions to .old, for example: zteitserprt.old
9. Now, unplug the BC-337.
10. Plug it back in and check the Device Manager.
11. Confirm if the virtual com port disappeared.