Why is Outlook not responding?

COM add-ins or large PST/OST files can block the UI thread.

How do I repair PST/OST safely?

Close Outlook, run SCANPST.EXE, repair then compact.

What if search is incomplete?

Rebuild Windows Search index and allow time for reindexing.

It helps diagnose add-in problems but you must disable or update offenders.

Should I recreate the profile?

Yes if corruption persists after repairs.

Does PC-Care.ai help automatically?

Yes - it trims startup load and clears temp files so Outlook runs smoothly.

Outlook Not Responding on Dell XPS - full guide and fixes

Outlook Not Responding on Dell XPS - causes, fixes, and prevention

Written by PC-Care.ai Editorial Team - Content Lead - Reviewed by PC-Care.ai Engineering - Windows Optimization - Last updated 9/14/2025

Overview - what this guide covers

We’ll walk through proven fixes and show how PC-Care.ai automates related maintenance.

Symptoms you might see

Outlook freezes when opening mail
Search results incomplete
High CPU while Outlook open
Startup slow after login

Not Responding occurs when COM add-ins block the UI or PST files are oversized. Search lag signals indexing backlog. High CPU points to scanning or background tasks.

Manual fixes - step by step

Start Outlook in Safe Mode
Disable COM add-ins
Repair PST or OST with SCANPST
Rebuild Windows Search index
Create new Outlook profile
Run PC-Care.ai to trim startups

Safe Mode starts Outlook without extensions. Disabling add-ins isolates offenders. Repairing PST files fixes structural corruption. Rebuilding the index cleans partial or corrupt entries. New profile clears profile-level corruption.

Prevention - keep the issue from coming back

Archive old mail and compact PST/OST regularly

Limit add-ins to essentials

Run PC-Care.ai weekly for consistent performance

How PC-Care.ai helps

PC-Care.ai reduces background CPU and trims startup apps for faster Outlook.

Typical results include smoother folder switching and fewer “Not Responding” popups.

Run Free AI Scan

FAQ

Why is Outlook not responding?: COM add-ins or large PST/OST files can block the UI thread.
How do I repair PST/OST safely?: Close Outlook, run SCANPST.EXE, repair then compact.
What if search is incomplete?: Rebuild Windows Search index and allow time for reindexing.
Is Safe Mode enough?: It helps diagnose add-in problems but you must disable or update offenders.
Should I recreate the profile?: Yes if corruption persists after repairs.
Does PC-Care.ai help automatically?: Yes - it trims startup load and clears temp files so Outlook runs smoothly.

References - further reading

Microsoft 365 support
support.microsoft.com/office/view-manage-and-install-add-ins
Outlook repair tool SCANPST
support.microsoft.com/office/outlook-repair-tool-scanpst

Outlook Not Responding on Dell XPS