The Edit Menu - Anchor controls option
Shortcut - Shift + Ctrl + A
Tool bar -

Normally the controls on a form will remain in the same place if the dimensions of the form change. This can cause problems as the controls will need to be realigned each time the form is resized. By anchoring controls on a form, the controls can automatically be realigned as the form size changes. Once in Anchor mode, the handles of each control are displayed. To select an anchor point simply click on the relevant handle.

This option is also available by right clicking on the form.