Go to start – run – and in there type: “Outlook.exe /resetnavpane” without the quotes. If this didn’t fix it, proceed with next steps:
Locate the Outlook executable file either in Program Files (keep in mind 32bit vs 64bit OS localization) or easier way: under Start – All Programs – Microsoft Office – Outlook. Right click the Outlook executable, navigate to compatibility TAB and if you see the checkbox for compatibility mode marked, you will have to remove it (uncheck it) and confirm with apply, ok and try to start Outlook again.
Repairing or reinstalling Outlook won’t fix it. This is an Outlook configuration issue.
If it still doesn’t work, re-create the Outlook profile from Sstart – Control Panel – Mail (show profiles – add – fill in and continue with the steps).
In most cases, re-creating the profile would fix it but you will have to add the archives and personal folders files again to this profile.
Recover and repair Microsoft Outlook PST files with competent and user-amiable Outlook PST Recovery software. When repaired, you can restore all the contents to an importable and fresh PST file. It also provides folder recovery.The software comes with new feel and look in its interface. Even the novice users can use this software. It features self-explanatory steps and you can control most of its tasks with one click.Free Trial Version you are eligible to see the preview of recovered emails in red items.Download link:- http://www.recoverfilesdownload.com/outlook-pst-recovery.html
You can try PST Repair solution that allows to fix all issue for corrupted or unreadable Outlook email folder without any data loss.