Adobe Digital Editions will not stay installed and I can't download library books

I have used ADE to transfer library books to my kobo for years but ADE went through a phase of constantly freezing when I tried to move a book over to my kobo. I uninstalled it and now I'm trying to reinstall it but it is not working. I have an icon on my desktop and can access books in my account but it does not allow me to borrow library books. It keeps asking me to allow the program to make changes on my computer and constantly goes through the installation process. The 'chat' experts have checked my ID/activation? and it's all OK. Over the past few months I have trawled through many forum posts and found lots people with the same problem as me but no solutions yet. I have used explorer and chrome, uninstalled my security, uninstalled the program etc.