There is no single Reset button in Word that restores every setting. Choose the fix that matches the problem: reset ribbon customizations, restore the default template for new documents, or repair Office if Word itself is malfunctioning. Save work and back up custom settings before a reset.
Restore the ribbon and Quick Access Toolbar
In Word for Windows, open File > Options > Customize Ribbon. Choose Reset > Reset all customizations to return all ribbon tabs and the Quick Access Toolbar to their defaults. If only one built-in tab is wrong, select it and choose Reset only selected Ribbon tab. Export customizations first if you may want them back.
Restore default formatting for new documents
New blank documents are based on Normal.dotm. If its styles, fonts, or margins were changed, close Word, make a backup copy of Normal.dotm, then rename the original and reopen Word. Word creates a fresh Normal.dotm with default settings. This affects new blank documents; it does not automatically reformat existing files. The new template will not contain custom styles, macros, or other customizations stored in the old one.
On Windows, Microsoft’s documented Normal template folder is the AppData > Roaming > Microsoft > Templates folder under your Windows user profile. On Mac, use Microsoft’s default settings for new documents instructions to find and back up Normal.dotm before changing it. If only one document looks wrong, check its styles and direct formatting before changing the global template.
To choose your own defaults afterward instead of Word’s originals, see setting defaults in Word.
If Word is crashing or behaving strangely
Use Microsoft’s Word troubleshooting and Office repair guidance for program problems. Repairing Office is different from resetting a document’s formatting or ribbon. Avoid deleting broad registry keys as a first step: they can remove unrelated customizations, and there is no one registry key that safely resets every Word setting.
Sources: Microsoft Support: customize the ribbon; Microsoft Support: Normal.dotm; Microsoft Support: troubleshoot Word.
Matt has been writing about Microsoft Windows and other Microsoft products since the days of Windows XP. He spends much of his time writing for sites like WindowBrain.com