problem

Arduino: 1.6.5 (Windows 8.1), Board: "Arduino/Genuino Uno"

Sketch uses 6,928 bytes (21%) of program storage space. Maximum is 32,256 bytes.

Global variables use 290 bytes (14%) of dynamic memory, leaving 1,758 bytes for local variables. Maximum is 2,048 bytes.

avrdude: ser_open(): can't open device "\.\COM3": The system cannot find the file specified.

Problem uploading to board. See Arduino Help Center for suggestions.

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

Select the correct port in the IDE.