Fix: Microsoft Word Using 100% CPU

Why Word Uses Excessive CPU

High CPU usage from Word makes your entire computer sluggish. Here are the common triggers and how to fix each one.

Step-by-Step Fix

Step 1: Disable Hardware Graphics Acceleration

1. Go to File > Options > Advanced
2. Scroll to the Display section
3. Check Disable hardware graphics acceleration
4. Click OK and restart Word

Step 2: Disable Background Spell Checking

For large documents, spell checking can consume significant CPU:

1. Go to File > Options > Proofing
2. Uncheck Check spelling as you type
3. Uncheck Mark grammar errors as you type
4. Run spell check manually when needed with F7

Step 3: Check Add-ins

1. Open Task Manager and note Word’s CPU usage
2. Close Word, reopen in Safe Mode (winword /safe)
3. Open the same document and check CPU usage
4. If lower in Safe Mode, disable add-ins via File > Options > Add-ins

Step 4: Simplify the Document

If the issue is document-specific:

1. Try selecting all content (Ctrl+A) and pasting into a new blank document (Ctrl+Shift+V for unformatted)
2. If CPU normalizes, the original document has corrupted formatting
3. Reapply formatting in the new document

Step 5: Check for Updates

1. Go to File > Account > Update Options > Update Now
2. High CPU bugs are often fixed in Office updates

Prevention

• Keep documents under 100 pages when possible
• Compress images before inserting
• Avoid deeply nested tables
• Update Office regularly