New to the list, but not new to Chirp.
Installed CHIRP in 2013 for my Baofeng UV-5R on my W7 PC. Installed the Prolific 3.2.0.0 drivers, programmed the radio with no problems. Lots of good advice on the Yahoo group.
Fast forward to 2017. Got a Kenwood TM-281A from a friend for a base station radio. Ordered a programming cable from an eBay vendor. Installed the Kenwood software, plugged in the cable and had no problem reading from and writing to the Kenwood.
Not real impressed with Kenwood's programming software. Decided to see if the radio is supported by CHIRP, downloaded the latest daily build and attempted to use CHIRP. Selected "Download from Radio, selected COM4, Kenwood and TM-281, and pressed OK. Nothing happens at all. If I repeat the process, an error is thrown: "An error has occurred. could not open COM4: [Error 5] Access is denied."
Did as much RTFM as I knew how to do. Read Beginner's Guide, read FAQ,
Noticed the driver had updated to Prolific 3.8.12.0; downgraded to 3.2.0.0. No change.