Originally published at: http://www.howtogeek.com/155803/how-to-change-the-default-paste-setting-in-microsoft-word-2013/
By default, when you paste text copied from elsewhere into Word 2013, you automatically get all the formatting with it. This formatting most likely does not match the rest of the content of your document and may not come in neatly.
Could you please check if these settings work when you uncheck the "Show Paste Options button when content is pasted" option? There is a bug in Office 2010 that makes Office ignore the default paste settings when this option is uncheck.
Thanks, Ruja, for mentioning this. I thought the paste options were not working at all, but I see that they do work when I reactivate the paste options button that I had disabled. Any idea if Microsoft is going to fix this?