Error opening serial port 'COM1'. (Port busy)
I've got an idea. Your board isn't being recognized. Try unplugging the arduino and see if Com 1 is still there. Sometimes it can recognize mice and other devices as Com 1 or 2 instead of your arduino.

On some of my development machines after everything settled out my devices will show up on Com 4 and 5 when I am working on two at a time.

If this is not the case go into the device manager and see if you can see the board listed.

I would also wonder if you have your sensor hooked to digital pins 0 and 1. These pins are used for your serial line on usb. So if you have anything such as a sensor hooked to them it may be generating data keeping the line busy instead of it being able to negotiate.

I had this happen when setting up hc-05 for the first time. I realized I had to keep the chip off while flashing or I would end up with errors or Com busy.

Please provide your pinout and basic information about the Com ports available on the ide. Also consider that you will need to specify the correct board as it will default to an uno. 

Programmer not in sync issues generally occur because the board is recognized but cannot be written to for one reason or another.


the board has something plugged into digital 1 and 0 which are serial i/o pins
the board programmer is busy running your last batch of code
usb error


So 


try a different cord
try unplugging potential wiring issues and see if it can be written to without anything on it
try holding down reset on the board until the board when you try to write to it until just after it finishes compiling to clear any potential programing issues


In my experience mega have a tendency to suffer from the last one.