1. Are you trying to perform the windowpane test on the entire ball of dough (first photo)? If so try to perform the windowpane test on a 2 inch piece of dough. Gently flatten the dough between two fingers. Then again, very gently stretch it.
2. Kneading is more than a fold, roll, and 1/4 turn. It's HOW you roll. The roll has to be a very smooth and light motion. The dough has a skin on it. That skin should never tear during kneading. The photo of the dough ball appears to have small tears in it.
Also based on the photo that shows you kneading, it appears the heel of your hand is pushing through the dough ball, then stretching it outward. That technique smashes, pushes, stretches, then tears the dough. That is not the correct technique of kneading. This video demonstrates correct kneading technique.
3. What type of flour are you using? A high extraction flour (such as whole wheat) won't windowpane due to the bran and endosperm. The coarse bits tear the dough as you stretch it.
4. What's in your dough? Is there anything besides flour, water, salt, and yeast? Any other additions will effect the windowpane test.
5. What type of flour are you using? The windowpane test really only works on refined (low extraction, finely ground) high protein flour, above 12%. You won't achieve it with all purpose flour as the protein content is too low.
6. Try adding a bit of vital gluten. Vital gluten will greatly improve the texture of your dough. You'll get better rise and a much lighter texture. Vital gluten is sold in stores like Whole Foods. The brand most readily available is Bob's Red Mill.
7. If after 15 minutes of kneading the dough doesn't pass the windowpane test, stop kneading. No dough should ever be kneaded longer than that. And if it doesn't pass that windowpane test, don't sweat it. Lots of experience bakers don't even perform the test.