What actually happened? Urgent!

Using Arduino Installation & Troubleshooting
#1

Hi,

At first I used Arduino to just run simple codes like this one:

void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
}

void loop() {
// put your main code here, to run repeatedly:
Serial.println(“Walid”);
}

And upload it to arduino and run it on serial monitor. But then I wrote a code :

void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
pinMode (A5,INPUT);
}

void loop() {
// put your main code here, to run repeatedly:
int pot = analogRead (A5);
Serial.println(pot);
}

and connected a potentio-meter at A5 and the side pins with 5 volts and ground. And it worked! I could see the values changing on serial monitor. But when I increased it to the max 1023 after a couple of seconds the software gave me an error saying :

Arduino: 1.8.2 (Windows 10), Board: “Arduino/Genuino Uno”

Sketch uses 1864 bytes (5%) of program storage space. Maximum is 32256 bytes.
Global variables use 186 bytes (9%) of dynamic memory, leaving 1862 bytes for local variables. Maximum is 2048 bytes.
avrdude: ser_open(): can’t open device “\.\COM7”: The system cannot find the file specified.

Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

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

So, now I don’t know what to do. Can you please help me with this issue?

Regards,

#2

First simple test, check if the correct port is selected in the IDE.

Which Arduino? Original or clone?

Check Windows' device manager if something changes when you connect/disconnect the arduino. Check the driver when the arduino is connected.

#3

and BTW you do not need to call pinMode. analogRead handles this automatically AND the pin defaults to input after startup anyway

#4