Problem while uploading to Nano

Using Arduino IDE 1.x
1 
Arduino: 1.8.4 (Windows 7), Board: "Arduino Nano, ATmega328P"



 int pulse(int interval=1){

                         ^

note: previous specification in 'int pulse(int)' here

 int pulse(int interval=1);

     ^

Sketch uses 12354 bytes (40%) of program storage space. Maximum is 30720 bytes.
Global variables use 612 bytes (29%) of dynamic memory, leaving 1436 bytes for local variables. Maximum is 2048 bytes.
avrdude: ser_open(): can't open device "\\.\COM5": 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.

Hii everyone
I'm using Arduino Nano in Windows7 OS. I don't understand what is the error with it.
When used same code and same hardware connections with windows10, it is uploading.
Thanks for any advice.

2