Once you have 4.2B or later installed,
Start PC Study Bible
Click on Options > Explore/Focus Mode Options
Click on Focus
Click on OK.
Now open the Bible passage you want.
Click on Links in the lower left of the screen.
Click the "+" in front of Cross-references > Commentary
Click on a commentary you want
That commentary should open *next* to your Bible, rather than in its own window on top of your Bible.
If you would like to see a Tutorial explaining this,
and you have a high-speed (faster than dial-up) internet connection,
Download the TUTORIAL BASE PACKAGE by this link.
Then download the specific tutorial about Explore & Focus Setup Options by this link.