For those who would like to test a .class file in a command prompt window in Windows, here is a technique.
Create the following batch file - ExecClass.bat:

Java Code:
REM Execute a java class file - need to strip extension
echo filename is %~n1
java %~n1
I have it in the folder: C:\BatchFiles

Use the Windows Explorer | Tools to add a commandline for the .class file:
Java Code:
C:\BatchFiles\ExecClass.bat "%1"
Open Windows Explorer
Click on Tools menu
Click on Folder Options
Select File Types tab
Scroll down in the "Registered file types:" list until you see an entry for class.
Select the class entry.
Click the Advanced button

give the action a name like: Execute class file.