How to: Draw a square in Paint.
Solution:
Click the rectangle tool, hold down the SHIFT key, and drag the mouse pointer.
NOTE: This solution assumes that Paint is opened.
1) Click the rectangle tool in the tool box.
Rectangle tool
2) Click a color for the rectangle in the color palette:
a) Select an outline color by clicking a color.
b) Select a fill color by right-clicking a color.
3) Click a fill style.
4) Hold down SHIFT and drag the mouse pointer to draw a square.