Everytime I open a PDF it opens in Edge ! how do I change this?

OK first you need to make sure Adobe Acrobat Reader is installed, if it is, click your start icon and type defaults this will search the system. Look in the list for Set Default Programs and click this option. Once running you will see a list of Programs. Find Adobe Acrobat Reader in the light, highlight it and click the option on the Right -> Set this program as default.