I am working on making a Prusa I3 3D printer as a senior project by using an Arduino Mega. so I have updated all of my software to the printer but when I have tried to update it by re-loading it into the printer, but when I try to upload the program the loading bar goes to 33% or so and stops. the IDE says Compiling sketch... but it never stops this. it doesn't say connection error, failure to compile or that the program has uploaded. I have even left this over night but nothing changes. I have restarted my computer 4 times and restarted the Arduino and even tried to burn the boot loader incase the loader is corrupt and when I try to re burn it, the IDE says that there is no USB device. though when trying to upload the program, it never says there is no USB device. WTF is the problem with my program, IDE, Computer??????????
Are you using Arduino IDE 1.6.5r5? One of the previous versions had a bug that caused that behavior. There's also a not in the Troubleshooting guide that gives another possible cause(and solution) on Windows: https://www.arduino.cc/en/Guide/Troubleshooting#toc7. Another thing you could try is to turn on File > Preferences > Show verbose output during: Compilation then you can see if it's consistently freezing on the same operation.
It may also be worth using an older version of the Arduino IDE. I am still using 1.5.6. The Arduino folks don't seem to have heard of backwards compatibility.
It is a simple matter to have several versions of the IDE on your PC.
...R