trouble with uploading sketch AnalogInOutSerial

Arduino: 1.8.5 (Windows 10), Board:"Arduino/Genuino Uno"

C:\Program Files (x86)\Arduino\arduino-builder -dump-prefs -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\x\Documents\Arduino\libraries -fqbn=arduino:avr:uno -ide-version=10805 -build-path C:\Users\x\AppData\Local\Temp\arduino_build_805870 -warnings=none -build-cache C:\Users\x\AppData\Local\Temp\arduino_cache_141383 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avrdude.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avr-gcc.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -verbose C:\Program Files (x86)\Arduino\examples\03.Analog\AnalogInOutSerial\AnalogInOutSerial.ino
C:\Program Files (x86)\Arduino\arduino-builder -compile -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\x\Documents\Arduino\libraries -fqbn=arduino:avr:uno -ide-version=10805 -build-path C:\Users\x\AppData\Local\Temp\arduino_build_805870 -warnings=none -build-cache C:\Users\x\AppData\Local\Temp\arduino_cache_141383 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avrdude.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avr-gcc.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -verbose C:\Program Files (x86)\Arduino\examples\03.Analog\AnalogInOutSerial\AnalogInOutSerial.ino
Using board 'uno' from platform in folder: C:\Program Files (x86)\Arduino\hardware\arduino\avr
Using core 'arduino' from platform in folder: C:\Program Files (x86)\Arduino\hardware\arduino\avr
Detecting libraries used...
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\standard" "C:\Users\x\AppData\Local\Temp\arduino_build_805870\sketch\AnalogInOutSerial.ino.cpp" -o "nul"
Generating function prototypes...
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\standard" "C:\Users\x\AppData\Local\Temp\arduino_build_805870\sketch\AnalogInOutSerial.ino.cpp" -o "C:\Users\x\AppData\Local\Temp\arduino_build_805870\preproc\ctags_target_for_gcc_minus_e.cpp"
"C:\Program Files (x86)\Arduino\tools-builder\ctags\5.8-arduino11/ctags" -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives "C:\Users\x\AppData\Local\Temp\arduino_build_805870\preproc\ctags_target_for_gcc_minus_e.cpp"
Bezig met het compileren van de schets...
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD -flto -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\standard" "C:\Users\x\AppData\Local\Temp\arduino_build_805870\sketch\AnalogInOutSerial.ino.cpp" -o "C:\Users\x\AppData\Local\Temp\arduino_build_805870\sketch\AnalogInOutSerial.ino.cpp.o"
Compiling libraries...
Compiling core...
Using precompiled core
Linking everything together...
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-gcc" -w -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=atmega328p -o "C:\Users\x\AppData\Local\Temp\arduino_build_805870/AnalogInOutSerial.ino.elf" "C:\Users\x\AppData\Local\Temp\arduino_build_805870\sketch\AnalogInOutSerial.ino.cpp.o" "C:\Users\x\AppData\Local\Temp\arduino_build_805870/..\arduino_cache_141383\core\core_arduino_avr_uno_0c812875ac70eb4a9b385d8fb077f54c.a" "-LC:\Users\x\AppData\Local\Temp\arduino_build_805870" -lm
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-objcopy" -O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0 "C:\Users\x\AppData\Local\Temp\arduino_build_805870/AnalogInOutSerial.ino.elf" "C:\Users\x\AppData\Local\Temp\arduino_build_805870/AnalogInOutSerial.ino.eep"
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-objcopy" -O ihex -R .eeprom "C:\Users\x\AppData\Local\Temp\arduino_build_805870/AnalogInOutSerial.ino.elf" "C:\Users\x\AppData\Local\Temp\arduino_build_805870/AnalogInOutSerial.ino.hex"
De schets gebruikt 2648 bytes (8%) programma-opslagruimte. Maximum is 32256 bytes.
Globale variabelen gebruiken 214 bytes (10%) van het dynamisch geheugen. Resteren 1834 bytes voor lokale variabelen. Maximum is 2048 bytes.
C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avrdude -CC:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf -v -patmega328p -carduino -PCOM3 -b115200 -D -Uflash:w:C:\Users\x\AppData\Local\Temp\arduino_build_805870/AnalogInOutSerial.ino.hex:i

avrdude: Version 6.3, compiled on Jan 17 2017 at 12:00:53
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is "C:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf"

Using Port : COM3
Using Programmer : arduino
Overriding Baud Rate : 115200
avrdude: ser_open(): can't open device "\.\COM3": Het systeem kan het opgegeven bestand niet vinden.

avrdude done. Thank you.

Probleem bij het uploaden naar het board. Zie http://www.arduino.cc/en/Guide/Troubleshooting#upload voor suggesties.

although all connections have been done correctly, as shown on page 117 (Arduino for Dummies, John Nussey)
I get the same error,
and now?

Is COM3 indeed the Arduino; you can check by disconnecting/connecting the Arduino and observing the device manager.