Sketches not uploading stk errors

Hi,

I have a Mega 2560 which i started using connected to a Dell XPS13 running Win 10 Home and the Mega 2560 worked fine and i was progressing through the basic lessons.

Time passed and the laptop got replace with a Dell XPS15 running Win 10 Pro and now i cant upload sketches.

Im using Arduino 1.8.13 installed from the App and again from the windows installer. Device manager shows Arduino Mega 2560 on Com 3 but the Arduino 1.8.13 window shows only Arduino on Com3 and attempting to upload the blink sketch results in

Arduino: 1.8.13 (Windows 10), Board: "Arduino Uno"

Sketch uses 924 bytes (2%) of program storage space. Maximum is 32256 bytes.

Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.

Error opening serial port 'COM3'. (Port busy)

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x09

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x09

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x09

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x09

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x09

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

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x09

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x09

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x09

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x09

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x09

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

Clearly i'm missing something but all of the above fixes except the cable swap dont do anything or the test results come back as they should

@martin31

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Is COM3 indeed the Mega?

Overly eager anti-virus? Try temporarily disabling it and check if it works.

According to your log, your board type is set to Arduino Uno, NOT mega. Make sure to select the correct board first.

arakon:
According to your log, your board type is set to Arduino Uno, NOT mega. Make sure to select the correct board first.

Great catch