Ans: To repair corrupt Outlook data files using the built-in SCANPST.EXE tool: 1. Locate SCANPST.EXE in your Outlook installation directory. 2. Run the tool and click Browse to select your PST file. 3. Click Start to begin the scan. 4. If errors are found, click Repair to fix them. 5. Once the repair is complete, restart Outlook and check if the issue is resolved.