ASP.Net page enter key causing post back

• You could set the DefaultButton on the Form or a Panel. This way you have full control what happens.
• Set UseSubmitBehavior="False" on your Buttons. This disables the "AutoPostback" on Enter.

I would prefer the second if i wanted to prevent Postbacks on Enter completely.

are you using jQuery?

if so:

$(document).keypress(function(e)
{
    if(e.keyCode === 13)
    {
        e.preventDefault();
        return false;
    }
});