It depends on the adobe version you have in your PC.

Yes. You are right. you can not save it untill you installed an adobe acrobat professionals in your PC.

You can download the form from USCIS website and save it to your disk. Then run the adobe acrobat professionals to open the pdf file you downloaded. You can save it.

If you don't have it, you cannot save your typing.

I have one adobe acrobat professions in my office PC, I tested, it works. However it does not work in my home PC. Only adode reader is not enough.

You can find any PC with that software installed. Good luck,