If the Arduino IDE won't start on Windows (the initialization window appears and disappears without showing any error message or warning), try running arduino_debug.exe from within the Arduino root folder, which is in C:\Program Files (x86)\Arduino\ by default.

If you get something like the following output there is an issue with the Java memory allocation.

Follow these steps to work around it:

1. In the Arduino root folder, open the file arduino.l4j.ini with a text editor.
2. Find the line starting with -Xmx. By default, it should be -Xmx512M. If this is not the case, change the line to read -Xmx512M.
3. Try running arduino_debug.exe again.

If it still gives the same error, the reason may be that the setting is being overridden by the _JAVA_OPTIONS environment variable. To test this, run the following command from the cmd command line in the Arduino root folder.

set _JAVA_OPTIONS=

From the same cmd session, run the exe.

arduino_debug.exe

The IDE should now start. But note that the _JAVA_OPTIONS is only unset in the current cmd session. To make the change permanent, it needs to be unset on the system and/or user level, which is outside the scope of this article. Note that setting the variable in this way may interfere with other applications on your system.