Keep the classic Windows look and feel on Windows XP

What look and feel are you currently using?

To set the native (windows in your case) look and feel see: http://javaalmanac.com/egs/javax.swing/LookFeelNative.html?l=rel

I'm using
UIManager.setLookAndFeel(
                    UIManager.getSystemLookAndFeelClassName());
or
UIManager.setLookAndFeel(
          "com.sun.java.swing.plaf.windows.WindowsLookAndFeel");


with the same result.  

The problem is it will set the XP look and feel and I want the classic Windows look and feel.
Basicaly I dont want the buttons and tabs  to hide the background color!

SetOpaque(false) wont work.

You can find/print your avaiable look and feel and pick something that sounds similar to what you are looking for:
 UIManager.LookAndFeelInfo[] info = UIManager.getInstalledLookAndFeels();
    for (int i=0; i<info.length; i++) {
        // Get the name of the look and feel that is suitable for display to the user
        String humanReadableName = info[i].getName();
   
        String className = info[i].getClassName();
        // The className is used with UIManager.setLookAndFeel()
        // See e867 Getting and Setting a Look and Feel
    }

Classic windows look and feel is most likely not available on XP.