Remove unused comports

1. Click start → Run → type regedit and click OK button
2. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\COM Name Arbiter
3. Now on the right panel, you can see the key ComDB. Right-click it and click modify
4. In value Data section set all to zero (00)
   Its 32 bytes with 8 bits in each byte in hexadecimal representation. A bit of value 1 makes a port number (1…256) reserved. The first 8 ports are in two leftmost hexadecimal values, bits ascending from lowest to highest right to left, the next 8 ports are in the second two and so on: hex F3 24 would be binary 1111 0011 0010 0100, which means that following ports are used: 1, 2, 5, 6, 7, 8 (1111 0011) and 11, 14 (0010 0100).
5. Set value to zero to remove all com ports
   

1. click Start / (right click:) Computer / Properties / Advanced System Settings (not Device Manager)
2. Click Environment Variables
3. Click in the System variables (bottom section) click New
4. Enter Variable Name: DEVMGR_SHOW_NONPRESENT_DEVICES
   Enter Variable Value: 1
5. Click OK (exits Environment)
6. Click OK (exits System Properties)
7. Click Start. In the command box, type Manage This shows the Computer Management window …
8. Click Device Manager
9. Click View and select Show Hidden Devices
10. Click Ports (COM & LPT)
    Now all the ports, real (black text) and phantom (grayed out text) appear.
11. One by one, right click the phantom ports, and select Uninstall

This should now have cleared out your system of unwanted phantom USB ports.

Note: after cleaning out all my phantom ports, leaving only “COM1”, I find my Registry shows: