How to compact the Windows Mail database in Windows Vista By Drew Mathers | October 1, 2015 1 1. Open Windows Mail. 2 2. Click: Tools 3 3. Click: Options 4 4. Click: Advanced 5 5. Click: Maintenance 6 6. Change the number 100 runs to 1. 7 7. Click: Close 8 8. Click: OK 9 9. Close Windows Mail. 10 10. Click: OK 11 11. Wait for the process to complete. 12 12. Open Windows Mail. 13 13. Click: Tools 14 14. Click: Options 15 15. Click: Advanced 16 16. Click: Maintenance 17 17. Change the number 1 runs back to 100. 18 18. Click: Close 19 19. Click: OK 20 Posted in Beginner