Some users have reported that a certain Windows update (KB5066835) causes PDF files to stop previewing in File Explorer, disrupting daily workflows that rely on quick document checks.
Until there is s a permanent fix, the safest approach is to prevent this update from installing automatically. Below are reliable methods Windows users can use to block KB5066835.
🚫 Method 1: Pause Windows Updates (Temporary Fix)
This method is quick but only delays the issue.
- Open Settings
- Go to Windows Update
- Click Pause updates
- Select the maximum pause duration available
⚠️ This only postpones the update. Once the pause expires, KB5066835 may install automatically.
🛑 Method 2: Hide KB5066835 Using Microsoft’s Show or Hide Tool (Recommended)
Microsoft provides an official troubleshooting tool to block specific updates.
Steps:
- Download “Show or hide updates” troubleshooter from Microsoft
- Run the tool
- Choose Hide updates
- Select KB5066835 from the list
- Complete the process and restart your PC
✅ This prevents Windows Update from reinstalling KB5066835 automatically.
📌 What to Do If KB5066835 Is Already Installed
If PDF preview is already broken:
- Go to Settings > Windows Update > Update history
- Click Uninstall updates
- Locate KB5066835
- Uninstall and restart
- Use Method 2 above to prevent reinstallation
🔍 Why This Matters
PDF preview in File Explorer is widely used for:
- Accounting documents
- Invoices and purchase orders
- Contracts and reports
An update that disrupts this feature can slow productivity, especially for businesses that handle large volumes of documents daily.
🧠 Final Recommendation
Until Microsoft releases an official fix:
- Avoid installing KB5066835
- Use Show or Hide Updates to block it
- Monitor future cumulative updates carefully before deployment
For businesses, testing Windows updates on non-production PCs first can help avoid downtime caused by unexpected bugs.