Unable to change port within IDE

Development Tools IDE 1.x
1

Arduino Mega 2560. I installed it on a previous PC, worked fine.

Installed on new PC, it shows up in Device Manager in the "Port (Com & LPT) section as "Arduino Mega 2560 (COM3)"

When I go into the Arduino 1.8.5 IDE > Tools > "Port:", I see "Port: (COM 1)"... (not COM3)

When I click on the ">" to the right of that, my options are "Serial ports" (which is grayed out) and "COM1" with a check mark.

My COM1 port is already in use.

How do I get Arduino IDE to recognize the Mega 2560 at COM 3?

Thanks.

2

(deleted)

3

Yes. Several times.

4

I learned that my Windows 10 PC needed a separate installation of an FTDI driver, which I downloaded and installed. My Windows 7 PC did not present me with that same issue. Don't know why. Either way, my Win10 PC now talks to the Arduino.