How to Convert .doc to .docx Files in Microsoft Word

1. Open the .doc document in Microsoft Word 2007 by double-clicking the document icon. Alternatively you may click the round symbol in the far upper left corner of the Word window, select 'Open,' select the .doc file you want to open, and click 'Open.'
2. Click the round symbol in the far upper left of the Word window. Highlight 'Save As' by hovering the mouse cursor over it, then select 'Word Document: Save the document in the default file format' from the options on your right.
3. Click 'Save' in the next window that opens. Even though it isn't immediately obvious, the 'Word Document' option means your file will be saved in .docx format. You file is now saved in the updated format.