Outlook includes a tool named that designed to repair damaged .PST files.
ScanPst scans and repairs the .PST file.

To fix outlook 2007 PST file:

1. Close outlook.
2. Browse to C:\Program Files\Microsoft Office\Office12.
3. Open file "Scanpst.exe"
4. Browse to point the location of the PST or OST file.
5. Configure is saving backup is needed.
6. Configure is fixing errors is needed.
7. Exit when done.
8. Open outlook 2007 and point to the PST if it’s not default.

Until Outlook 2002, ScanPst doesn’t support PST files which run over 2G size.
in that case Microsoft shared the PST2GB tool, can be downloaded from here:
http://www.microsoft.com/downloads/details.aspx?FamilyID=B33B1DFF-6F50-411D-BBDF-82019DDA602E&displaylang=en
PST2GB may cause messages disappear.
After extract the EXE file:

1. Copy the msstdfmt.dll and msvbvm60.dll files to the system directory.
2. Click Start and Click Run
3. Type regsvr32 < Type_msstdfmt.dll_path_here>
4. Click OK.
5. Run Scanpst.exe.