> With D3, I created a simple program using ActiveForm.
> I use MSExplorer 4 Browser and I get my ActiveForm runs normally,
> but when I close this browser I will get crash,.....

This is because Delphi 3's ActiveForms do not support the Apartment
Threading model (which is required for IE4). Your D3 ActiveForm will
work (and exit) just fine in IE3, but for IE4 you need Delphi 4...