Thoroughly solve the problem of COM port occupation (in use)

Today I encountered this problem. When debugging the serial port, I found that the USB-to-serial port uses com8 and the serial port debugging assistant only contains COM1 to 4. I want to go to this COM port and find that COM1 to 7 are in use, I can't find a lot of methods. I will find this solution article on the Internet and repost it. It's a little bad if I didn't mark the address for reprinting. Hey hey. Thoroughly solve the problem of COM port occupation (in use) 1. How to release the occupied comport? Due to repeated installation of different versions of Bluetooth drivers ~ After the driver is successfully installed, only com16 can be used and the synchronization software does not recognize it. Which of the following experts can explain? Thank you! 2. when using USB to serial port Devices, due to problems with the previous devices, after changing the device, we found that all the previously used comports are currently in use, the number of new comports assigned by the device starts from the previous days. For example, if you tried COM7 before, the number of com8 is displayed after you changed the device, the COM2-COM7 is displayed in use (COM1 is retained by machine) 3. How do I delete the COM port used in my computer? My computer often uses Bluetooth, mobile phone data lines, and other things. Every time a new device is installed, Windows will automatically allocate a new virtual comport. Now, all new devices are inserted with com25, view Device Manager-Port-com25 properties-port settings-advanced-COM port number, found from 3 ~ 24 is all "in use". How can I delete the previous items? Complete solution to the above problems: Open the Registry HKEY_LOCAL_MACHINE/system/CurrentControlSet/control/com name arbiter Delete comdb and try again! (Note: All comports will be rebuilt ). If not, restart your computer! Note: The above method solves my problem ...... You can also check whether the Integrated modem occupies your serial port. Open "phone/MODEM options" in "Control Panel ", On the modem tab, is there a connection that occupies this serial port (such as COM1) Solution: If a connection occupies this serial port, delete the connection and restart the computer to solve the problem. Or see the detailed reason: 1. Start in safe mode and test the serial port (COM1) with the "Super Terminal" in the system-provided communication ), At this time, the same error is reported, but the error information is more detailed, as shown below: * ****** Error message ******** Windows reports a TAPI error (80000048 ). Use "phone/MODEM options" in "Control Panel" To verify that the modem is correctly installed. ********************** 2. Start the computer properly. Open "phone/MODEM options" in "Control Panel ", We found that a connection on the modem tab occupies this serial port (COM1 ), Delete the connection immediately. Use "Super Terminal" to test the serial port (COM1). No error is reported, Indicates that the communication with the serial port (COM1) is normal. 3. Connect the serial port device to the serial port (COM1) and communicate with the device using related software. The problem can be solved normally. About the problem that the comport is occupied when a bluetooth device is used Due to the inexplicable registry of windows, many users find that after installing the Bluetooth management software, the corresponding Bluetooth virtual port is actually changed to com9, or even com13 or higher, as a result, the synchronization software with many applications, such as mobile phones and PDAs, cannot be used. Re-installing the Bluetooth management software multiple times will only make the situation worse .. The solution is as follows (before performing the following steps, be sure to uninstall the Bluetooth management program and reboot) 1. In Windows, press Start> RUN> Enter cmd and press Enter. 2. After the command character window appears, enter Set devmgr_show_nonpresent_devices = 1 Press ENTER Devmgmt. MSC Press ENTER 3. Click> View> display hidden devices in the Device Manager. You can delete unnecessary ports now. After deleting the ports, Please restart them. 4. reinstall the Bluetooth management software. 5. If you want to permanently input this environment variable to XP, go to my computer> click, right-click, and choose Properties> advanced> environment variable In the system variables, press "new", enter "devmgr_show_nonpresent_devices" in "variable name", and enter "1" in the variable value" I will only post this post to my friends who have made unremitting efforts on the way to using Bluetooth (the ultimate solution for the comport