Accidentally changed an annotation in my ADE annotations folder to open with PDF, It has changed them all. How can I change them back or is it ok to delete the whole folder

I went into my documents/ ADE and opened the annotations folder.  I changed the read with on one to PDF and it has changed them all.  How can I change it back.  Or is it ok to delete the whole folder. I don't have any annotations I want to save.