Resolving USB driver issues
Method Using Elevated Command Prompt
ie type cmd in search bar then right click cmd.exe selecting Run as Administrator
• 1st stage As discussed from command prompt type;
Under Ports (Com & LPT) delete all instances of prolific USB to Serial Comm Port
• 2nd Stage Again from Elevated Command Prompt - Remove Driver Packages from drivers store.
The driver store is a protected area of the computer that contains device driver packages that have been approved for installation on the computer
You need to Identify OEM#.inf where # is a number so type
pnputil.exe -e (then enter)
Read the entries in the output to find the description of your package(s) and its file name(s)
Its highly likely you will have multiple entries from previous attempts.
Note all oem###.inf instances of the prolific driver where # (hash) is the number.
To remove entries type:
pnputil.exe -d oem###.inf
(use space between exe & - and d & Oem then press enter)
Remember to replace # with the number of the inf file you want to delete.
If the computer reports that the driver package is in use by a currently installed device, then you must either uninstall the device first, or use the -f on the pnputil command to force deletion of the package.
Also you may have driver package loaded on as program that may need removal using control panel/programs/uninstall a program.
If you do all that before loading the correct driver package and try to keep the Com device inserted in the same port rather than moving it around your ports you will have fewer problems with the Prolific driver.