Registry Hack: Modify the Undo Limit in Microsoft Office

By default, Microsoft Office apps like Word and Excel only let you undo your last 100 actions. That might sound like plenty—until it’s not. If you’re editing a large document, working with formulas, or just like having a longer safety net, that 100-step limit can get in your way fast.

Here’s the good news: you can change it. All it takes is a simple registry tweak.

⚠️ A Quick Warning

Editing the Windows Registry isn’t dangerous if you know what you’re doing, but mistakes can mess up your system. Back up your registry before making changes.

🔧 How to Change the Undo Limit in Microsoft Office

This tweak works for Microsoft Word, Excel, and PowerPoint.

Step 1: Open the Registry Editor

1. Press Win + R, type regedit, and hit Enter.
2. If prompted by User Account Control, click Yes.

Step 2: Navigate to the Office Key

You’ll need to go to a path that depends on your Office version. Here are some common paths:

• Office 365 / Office 2019 / 2021 (16.0): HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\<AppName>\Options

Replace <AppName> with:

• Word for Microsoft Word
• Excel for Microsoft Excel
• PowerPoint for PowerPoint

For example, for Word:

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Word\Options

Step 3: Create the UndoHistory Registry Value

1. Right-click in the right pane and select New > DWORD (32-bit) Value.
2. Name it: UndoHistory
3. Double-click UndoHistory and set the value (Decimal) to your preferred limit. For example:
   • 200 for 200 undo levels
   • 500 if you want to go big

⚠️ Microsoft officially supports values up to 1000. Going beyond that might cause performance issues depending on your system.

Step 4: Restart the App

Close and reopen Word, Excel, or PowerPoint. Your new undo limit is now in effect.

💡 Pro Tip

This tweak is user-specific and app-specific. Want it in both Word and Excel? You’ll need to repeat the process for each app.

🧼 Want to Revert?

No problem. Just go back to the same registry location and either:

• Set UndoHistory back to 100
• Or delete the key entirely

Final Thoughts

The undo feature is a lifeline when editing complex documents. Bumping the limit gives you more room to work without fear of making irreversible mistakes. It’s a small tweak, but a powerful one—especially for writers, editors, analysts, and power users.

Bookmark this trick and make Office work better for you.