Yes you can. Handle OnKeyDown.
That might prevent the hint, but you cannot alter the text of the Windows balloon tip AFAIK.
You would also have to handle pasteing into the control to avoid the balloon tip.
If you want to go to that hassle better use a TMaskEdit (and see how difficult it is to prevent unwanted pasting).
You might want to consider using a TSpinEdit(Ex) or a TFloatSpinEdit(Ex). These are specifically designed to handle numeric input, and they have a property Value, whic will give you an integer (or float) right away.
Bart