OpenIMU 300ZA EVK serial port connection problem

I have been using OpenIMU 3ooZA EVK under Windows 10 for a while. it all works fine until recently. After a reboot of the device the Windows Server 1.1.1 just keep Testing ports ...

I checked the port (in this case COM 7 ) by HTerm, it shows >> Erro in Open Port: COM 7 blocked by another application

Well, I tried to search all process that may occupy the port, Nothing found!
also tried to reboot PC, change USB port, Unplug all other usb devices, replug etc. NO Luck.

I somehow ran out of idea. Strange thing is it worked just fine before the reboot of EVK. Any advice would be much appreciated!!

Hi, please find another PC and use HTerm to check whether the EVK can work properly or not at first, I think maybe something wrong with the USB 2 Serial port driver on your PC, you can check and reinstall it.