The Microsoft Edge Browser allows for annotations to be done natively.
If you browse a pdf and open it, the annotation options will be available right inside the browser. If you have a pdf file that you would like to annotate using Microsoft Edge, simply use the Open With option and select the Microsoft Edge option. If you have not installed any other pdf viewers on your computer, Windows 10 will use Microsoft Edge as its default pdf viewer.
Once the document is open in the browser...
Simply highlight the text you would like to add a comment to or highlight. An options menu bar will appear. Below is an example of highlighting a section of text. Selecting the highlighter icon will bring up the color options for the highlighter.
Click the comment icon.
Once you've finished your comment
Be sure to select the checkmark in the upper right corner of the comment box to save it.
Be sure to save all of your changes.