In the following section, you perform additional configuration that is optional but will greatly improve performance and usability in the context of the development work you are about to start with the tutorial.
On Windows 32 bit, if you increase the Xmx too much, then you cannot use the PermSize parameter. The heap size is calculated as -Xmx + PermMaxSize. If these two add up to more than 1408 MB then WLS will not start.
Here is the recommendation for Windows 32 bit:
set DEFAULT_MEM_ARGS=-Xms512m ...