title: Why do I need java.net.preferIPv4Stack=true only on some windows 7 systems?
body: <p>I have used Java on Windows 7 (64bit) machines for quite some time and have never had problems with not being able to create a network connection. Now on the systems at the company I'm working for I need to set "-Djava.net.preferIPv4Stack=true" or it seems the java processes are not able to create a single connection.</p>
  
  <p>The downside is that if I don't set "_JAVA_OPTIONS" I would have to configure tons of services to use this setting. However if I use it Java outputs this silly "Picked up: _JAVA_OPTIONS..." to stderr (Wonder which guy made that silly decision). This however makes my GWT compiles fail in IntelliJ.</p>
  
  <p>What I would like to know ... this is the first time I'm having these problems and I guess they must somehow be related to the setup of the Operating System. What is probably causing these problems (As I mentioned ... I have about 4 other Systems with windows 7 and 64 bit java vms that don't have these problems).</p>
  
  <p>Chris</p>