The problem is probably that the non-working driver is the newest (September 2021 vs. Unfortunately neither ProSim737 or ProSimMCP will recognise COM3. Re-installed the CPFlight software and driver. Uninstalled 'Communications Port (COM1)' and 'Prolific USB-to-Serial Comm Port (COM3)'. I had only one other entry, a "ser2pl.inf" version " 3.8.40.0".ĭisconnect the device, and "pnputil /delete-driver oemXY.inf" with the INF file you located in the previous step.Ĭonnect the device again, and it should work, at least, it does for me. ProSim737 and ProSimMCP both want to assign COM1. Click on Let me pick from a list of available drivers. Right click on the Prolific item in the list and click on Properties. Expand Ports (Com & LPT) and then right-click Prolific USB-to-Serial Comm Port (Com5) to Update Driver.
Then "pnputil /enum-drivers", and in the output look for Prolific drivers other than the ones from the previous step. After installing, go to the Device Manager and find the device listed under Ports (COM & LPT). Unplug all USB-To-Serial adapters from your computer. It will add the two driver packages to the driver store and tell you what oemXY.inf files it has assigned to them. I don't recommend other vendors for these devices because WHQL drivers are few and far between. There are several vendors of USB to Serial Adaptors that use the Prolific PL2303 chipset.
What I did is this:įirst install the downloaded driver by unpacking the zip file and "pnputil /add-driver *.inf /subdirs /install" (the /install is probably not necessary) from the extracted "Win11_DCHU" directory. Handshake problems or data errors can be caused by a number of issues including USB Port power management which. Getting it installed is a bit tricky, it seems. There is a working driver at, a bit down the page listed as "DCHU (for PC Vendors)". Download the driver from Prolifics site (also attached, however the link will provide the latest version).