Java Crashing Windows

There were cases before of crashes under windows on IBM Thinkpads (and other machines I am sure) due to a bad graphics driver. I'd suggest doing the usual thing of making sure the drivers are up to date just to be on the safe side.

While your code may not use JNI directly a lot of what happens under the hood can (anything that integrates with the underlying OS essentially). Which means drivers can be a big problem.

The other thing would to be sure that the most recent version of the Java is being used (if 1.6_17 isn't possible at last the latest version of the version of Java being used).

One other thing that has fixed random crashes for me is to re-seat the memory (unplug it and plug it back in).

he said it freezes everything in Windows (his mouse doesn't even move)

A user-mode application — whether Java or otherwise — can't do that against a modern OS like WinNT.

He either has a hardware problem, or a bad driver.

To crash the entire computer, try this:

public void crashComputer() {
    while(true)
        new Thread(new Runnable() {
            @Override
            public void run() {
                while(true) {
                    crashComputer();
                }
            }
        }).start();
}

public void crashJVM() {
    while(true)
        crashJVM();
}

The crashComputer function takes about 2 seconds to crash the entire computer. You can stop it from crashing by holding power button.

The crashJVM function crashed only the JVM by overloading the stack, causing a stack overflow (That's where the name of this website comes from).

WARNING: Use at your own risk. This will not damage your computer, but I'm not taking the blame if you forget to click save on a document or something.

Also check the page file space on the client (Windows/XP) system.

Point one: On my XP, SP3 system, when any program runs full tilt, it almost locks up the computer. When my anti-virus program checks for updates, everything else stops for all practical purposes, and it uses very little CPU (seems to be writing to disk all the time). My own infinite loops, using 100% CPU, have a similar effect. (Why the task manager does not get priority over a user program with "normal" priority I do not know.)

Point two: On any computer I've ever used, heavy paging will bring a program to an almost complete stop.

So start with an XP computer with 512Mb of real memory and 2000Mb of virtual memory. Write a Java program with 1400Mb worth of arrays and other data structures. Put in a loop that repeats several billion times and reads or writes to each byte in that 1400Mb on each execution. This program will not finish until long after the universe collapses in on itself. The computer will do nothing. I have not tried this and I do not intend to, but I will bet anything even the mouse won't move. Depending on the make of the computer, the only fix may be pulling the power plug out of the wall socket. (Note that technically, the computer has not crashed. Indeed, it is working just fine. But you are going to need to be patient. Move the mouse the day before you plan to click.)

The moral of this story is to avoid both XP and virtual memory, but if you have to deal with either, be aware of these problems.