Norton Security Scan pop up not letting my ADE complete downloading

​My ADE was working fine...I downloaded a book from Overdrive and it put it on my Kobo ereader,, but it didn't dl properly as I could not open it on reader. Then ADE stopped responding and completely wiped out everything on my Kobo ereader so I had to reset it to factory settings. I can now download books straight from Kobo site, but ADE is gone, and I have tried several times to download it but it almost finishes (has only 1 or 2 spaces to go) then Norton Security Scan pops up and I cant get rid of it and I think I would have to "agree" to scan to finish dl of ADE.  I DO NOT WANT NORTON SCANNING MY PC.  The only way I can get rid of the pop-up is to go to task manager and "end task".  So now I cannot get books from my library thru Overdrive on Tracpac. Anyone else have this problem?