I noticed that nobody answered with a more sophisticated andswer, and so
her're my simpleton one.

First, if you having an actual malfunction (vs. just needing scrollbars) you
should re-post with more detail on that.

If you consider it important to avoid scrollbars, design your screen so that
looks OK on the lowest resolution screen / setting that will cover 99% of
your users. Probably 600 x 800.

You didn't say what resolution your laptop is / is set at. If it's lower
than 600 x800, unless it's older than me, you should be able to reset it's
resolution up to that.