We can't provide detail - we don't know your application, and how it is configured.
There are some things you can do:
Checkbox.Checked = false;
will reset an individual checkbox state.
TextBox.Text = "";
Will reset an individual Textbox.
You can loop through the Controls array:
foreach (Control c in Controls)
{
if (c is CheckBox)
{
((CheckBox) c).Checked = false;
}
else if (c is TextBox)
{
((TextBox) c).Text = "";
}
}
And you can modify this to handle those inside Panels and other container controls.
If you have CheckBoxes or text fields inside custom controls, though, you will have to work out your own way of dealing with them.