Lloyd,

There is no attached project, anyways it is not a good idea to post
attachements in the ng.

I tried to add NumericUpDown control to a from. I pressed the button it
increased the value. I delete the value in the edit box and pressed the
button again it new increased value showed up.

If this is the situation in your project my best guess is that you do
something else in the code.

Num.Text = num.Value.ToString() works.

After you delete the 42 the Value property remains the same probably because
no entry is not a number so the 42 remains as the Value. This gives you the
chance to get the value before it was deleted. Because you are not changing
the Value when you set it to 42 the second time then the control is not
calling it's internal methods to cause the value to display as nothing has
really changed. You need to decide what "no entry" means in terms of a
numerical value and set the control's Text property to what you want
displayed, i.e. either 0 or to the Value.ToString(). Generally most controls
show 0 when you leave the control empty.

HTH

SP