It seems that the Label has no Hint or ToolTip or Hovertext property. So what is the preferred method to show a hint, tooltip
Label
Hint
ToolTip
Hovertext
You have to add a ToolTip control to your form first. Then you can set the text it should display for other controls.
Here's a screenshot showing the designer after adding a ToolTip control which is named toolTip1:
toolTip1