Hi,
Thank you for posting your query in Microsoft Community.
From your issue description I understand that, all the apps are opening in full screen mode. If I am wrong, please let me know.
All the apps will open in full screen mode it is by design and we cannot turn it off. It is the main feature of Windows 8, and it is also called as modern Interface.
http://technet.microsoft.com/en-us/windows/explore-windows-8.aspx
Hope this helps. If the issue persists or any Windows related queries or issues related to Windows Operating system, please get back to us. We are here to assist you.