How to Install a new Arduino UNO ??

Dec 2018
How to Install a new Arduino UNO into Windows 10 Desktop computer , with Ard IDE 1.8.1

I am a newbie, but there has been progress: I still have a my_Arduino_UNO that still works !
As a backup I purchased 3ea Arduino UNO from China, but they DID NOT OPERATE.

Finally after months of fruitless reading and learning, I checked my computer settings using my_Arduino_UNO was loaded using File/Examples/.01 Basics/BLINK as a reference.

my_Arduino_UNO worked and changed the BLINK from 1/sec to 1/15sec
the following readout shows my computer settings
Windows 10/Control Panel/Device Manager/Ports(COM&LPT)
USB Serial Device (COM4)

Each of the new Arduino UNO finally operated BUT only after I changed the computer settings from
Windows 10/.................................. er/Ports(COM&LPT) \ | /
USB Serial Device (COM7) ! !
/ |\

All 3 units work fine when COM7 is changed to COM4 !!!!

QUESTION:
(1) Is this normal? must every new Arduino UNO be checked for this type of change ??
(2) How can the Arduino UNO effect the computer settings...is there something in Arduino IDE 1.8.1
that causes COM7 to appear ??

martymarty

(deleted)

martymarty:
QUESTION:
(1) Is this normal? must every new Arduino UNO be checked for this type of change ??
(2) How can the Arduino UNO effect the computer settings...is there something in Arduino IDE 1.8.1
that causes COM7 to appear ??

It's normal that an operating system assigns a different port to an Arduino; it sometimes happens and sometimes it does not. Nothing to worry about; just select a diferent port in the IDE.

You don't want all Arduinos to all have the same port because that way you can never use two or more at the same time.