[2005] binding ENTER to button

How can I make one button to be default on one form for pressing Enter key?

Set the form's AcceptButton property to that button.
Depending upon the purpose of your form, you may or may not also want to set the DialogResult property of the button to some value.

It would probably be easier to put the code that is in your button click into it's own sub/function and then use the form keypress event to run the same code when you hit enter

Edit: or what he ^ said

Thanks guys, problem solved.