this is probably a silly question to most of you. Ive just got my new board but cant launch the Arduino API. when I try to use the Arduino.exe or run.bat i get error: “Java Virtual Machine Launcher: Could not find the main class. Program will exit.” Online resources suggest the presence of adware or the like interfering. I know this is not the case. Please help!

Not a silly question at all - a difficult one in fact.

Which version of Arduino? Which version of Windows? Can you post the contents of your the “lib” directory of the Arduino software? Do you have any funky extended unicode characters in the path to the Arduino software?

Im currently using the updated Arduino version 0004 package downloaded and unpacked right from Arduino’s software page onto my desktop. the path therefore is "C:\Documents and Settings\Dupree\Desktop\Arduino\arduino-0004-win\Arduino.exe " I’m running windows xp pro V.2002 SP2. The contents of my Arduino lib folder should be exactly whats in the Arduino download. I havent changed anything. Should I have changed something? Im having the exact same problem running “Processing” API as well. I think my Java install may not be right, but then again, regular java programs are working fine. (I dont know squat about Java (v1.4.2), just installed it to run the Arduino API)(which i may or may not have needed to do?) Your help is appreciated!

You can try using the version of Java that you installed yourself (which ordinarily you shouldn’t need, as one comes with Arduino for Windows). Edit the run.bat file and change the line:

set JAVA_HOME="java\bin"

to the appropriate path to your Java install. E.g. something like:

c:\program files\j2re1.4.2\bin

You might need to put a backslash or two before the space in “program files”.

hey, i have had the same problem. i tried arduino version 003 and 004. i changed the java path to the bin directory. i can open arduino by doubleclicking the run.bat. but if i try to open the execute file i get an error message.

yea…boy i feel dumb now that i figured out the problem. I was extracting the files by opening winzip and drag’n’dropping the files to a folder instead of properly extracting them with “extract to”. Thus the file system was not correctly setup and the program didnt work. but i dint know what the file system within was supposed to look like. Im dumb. Dont take shortcuts.

sonderformat: what error message do you get when you click the arduino.exe?