Trying to get my mega 2560 to work for my 3d printer Trying to pit marlins v2non this board and it gives me an error and I have no idea what to do

Arduino: 1.6.10 (Windows 10), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

Sketch uses 85,558 bytes (33%) of program storage space. Maximum is 253,952 bytes.
Global variables use 3,606 bytes (44%) of dynamic memory, leaving 4,586 bytes for local variables. Maximum is 8,192 bytes.
avrdude: ser_open(): can't open device "\\.\COM4": Access is denied.


avrdude: ser_drain(): read error: The handle is invalid.


avrdude: ser_send(): write error: sorry no info avail
avrdude: stk500_send(): failed to send command to serial port
avrdude: ser_recv(): read error: The handle is invalid.


avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: ser_send(): write error: sorry no info avail
avrdude: stk500_send(): failed to send command to serial port
avrdude: ser_recv(): read error: The handle is invalid.


avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: ser_send(): write error: sorry no info avail
avrdude: stk500_send(): failed to send command to serial port
avrdude: ser_recv(): read error: The handle is invalid.


avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: ser_send(): write error: sorry no info avail
avrdude: stk500_send(): failed to send command to serial port
avrdude: ser_recv(): read error: The handle is invalid.


avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: ser_send(): write error: sorry no info avail
avrdude: stk500_send(): failed to send command to serial port
avrdude: ser_recv(): read error: The handle is invalid.


avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: ser_send(): write error: sorry no info avail
avrdude: stk500_send(): failed to send command to serial port
avrdude: ser_recv(): read error: The handle is invalid.


avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer
the selected serial port avrdude: stk500v2_getsync(): timeout communicating with programmer
 does not exist or your board is not connected

This report would have more information with
"Show verbose output during compilation"
option enabled in File -&gt; Preferences.
COM4 ... assuming it's a windows host, then?

All those errors may be because the COM port specified doesn't exist. (changed and/or not seen)

0.) Has this mega ever had a sketch uploaded successfully before this? (for anything)

1.) Have you verified within the arduino IDE that COM4 is showing up in the ports menu?  (Tools => Ports)

2.) Did you plug the arduino into a different USB port?  (sometimes when it's re-recognized it'll assign a different COM port)  

If it's changed COM port, then (obviously) change the port designation in the IDE.

Try switching it to a different USB port and waiting for device manager to recognize it.  If that doesn't work and the mega worked before update the question with the above info and we'll try again.