title: Java maximum memory on Windows XP
body: <p>I've always been able to allocate 1400 megabytes for Java SE running on 32-bit Windows XP (Java 1.4, 1.5 and 1.6).</p>
  
  <pre><code>java -Xmx1400m ...
  </code></pre>
  
  <p>Today I tried the same option on a new Windows XP machine using Java 1.5_16 and 1.6.0_07 and got the error:</p>
  
  <pre><code>Error occurred during initialization of VM
  Could not reserve enough space for object heap
  Could not create the Java virtual machine.
  </code></pre>
  
  <p>Through trial and error it seems 1200 megabytes is the most I can allocate on this machine.</p>
  
  <p>Any ideas why one machine would allow 1400 and another only 1200?</p>
  
  <p>Edit: The machine has 4GB of RAM with about 3.5GB that Windows can recognize.</p>