EPUB has become a standard ebook format, but Microsoft has made downloading the files frustrating. Internet Explorer often renames the POP.epub file you need, turning it into POP.zip. This is fixable in a few simple steps.

1) Write down where you downloaded the POP.zip file on your computer

2) Right click the Start button or Microsoft symbol in lower left of your screen and Open Windows Explorer.

3) Find the POP.zip file.

4) Do you see "POP.zip"? If so, skip to Step 6. If you only see "POP" as the file name, continue on to Step 5.

5) To see the ".zip" extension

Open Control Panel from the Start menu.

Choose Appearance and Personalization.

Choose Folder Options

Click the "View" Tab

UNCHECK "Hide extensions for known file types"

Hit OK