Are you certain it is using the Microsoft Office version of Outlook? Microsoft has been changing Hotmail for a while now, and they are calling the free email service Outlook also. Yes, very confusing.
If you sign into Hotmail, and find yourself in the Outlook layout, look for the gear symbol at the top right of the window. Click on it and you'll see a drop down list of settings. The last one should read "Switch back to Hotmail". Click on this one to return things to the older style Hotmail look.
This ability to switch back to Hotmail settings may not be around for long though, as Microsoft is trying to distance themselves from older styles and older graphics.