I had the same problem. As a graphic designer, I need my PDF source materials viewable in windows around my 27" monitor -- not full-screen in that awful app. I also couldn't edit or delete the PDFs half the time, because they were still open in minimized
Reader.
By default, Windows opens PDFs in the Reader app. Change the default program to
Acrobat (Pro or their free Reader version.) This solved my problem, and I'm back to having PDFs in separate windows I can move around my screen.
- Right-click on a PDF file, choose Open With > Choose default program
- Check "Use this app for all .pdf files"
- Select Adobe Acrobat, or Adobe Reader, etc. (Not the Windows "Reader" app with the red book icon)
Enjoy!
Windows 8 has a built-in MS PDF reader, which always defaults to fullscreen, and cannot be changed. The "issue" here comes from the MS implementation of the Windows 8 Tiled apps.
Download an external app, like Adobe Reader, and open the PDF with that app, and you can open the PDF in a window just fine.