How To Identify Default Java Heapsize In Windows

Im running an eclipse application in my machine. I have two queries

1. I would like to know how to check the default heap size that the jvm is using to run the application.Im using a windows machine to run the java application. I tried to check the default heap size by the following way
ControlPanel--->Programs--->JavaSetting--> JavaTab -->View Button ---> JavaRuntimeEnvironment settings window ---> Userstab --> Value under RuntimeParameters

But in my system, there is no runtime parameters defined. Is there a command that I can execute via command prompt to check the default heap size in my machine.

2. How to increase the heap size parameter and run the eclipse plugin application from command prompt. For eg: To increase the heap size and execute the jar file we use the below command java -Xms64m -jar MyApp.jar. I would like to know how to set heap parameters and execute my java application which is an exe file. I tried to execute use the below command, but the command prompt doesnot recognise the command

java -Xms512m iepsd.exe

Where iepsd.exe is my java application.