Every time I try to upload a sketch this error message comes up
Arduino: 1.8.7 (Windows 10), Board: “Arduino/Genuino Uno”

Sketch uses 4064 bytes (12%) of program storage space. Maximum is 32256 bytes.
Global variables use 291 bytes (14%) of dynamic memory, leaving 1757 bytes for local variables. Maximum is 2048 bytes.
C:\Users\Amy Schemitsch\Arduino\hardware\tools\avr/bin/avrdude -CC:\Users\Amy Schemitsch\Arduino\hardware\tools\avr/etc/avrdude.conf -v -patmega328p -carduino -PCOM5 -b115200 -D -Uflash:w:C:\Users\AMYSCH~1\AppData\Local\Temp\arduino_build_573851/FlowMeterDIY.ino.hex:i

avrdude: Version 6.3-20171130
Copyright (c) 2000-2005 Brian Dean,
Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is “C:\Users\Amy Schemitsch\Arduino\hardware\tools\avr/etc/avrdude.conf”

Using Port : COM5
Using Programmer : arduino
Overriding Baud Rate : 115200
avrdude: ser_open(): can’t set com-state for “\.\COM5”

avrdude done. Thank you.

An error occurred while uploading the sketch

This report would have more information with
“Show verbose output during compilation”
option enabled in File → Preferences.


That's a driver issue.

I think all the times I've seen it described here it was from a clone board (I think always ch340g based) on windows 10 for which drivers had not been installed. Unlike previous versions of windows, win10 (at least in some update-states) recognizes that the CH340G is a serial interface, but doesn't have drivers for it that work. In these cases, installing the correct driver has sorted it out. The driver for CH340G and CP2102 are not included with the IDE, as there are no official boards that use those (only clones), and the IDE doesn't supply drivers for third party boards, even extremely popular ones.