At this point there are really only three things I can think of to try:
1) You can run the Software Verification Tool (found in Windows by going to Start>All Programs>Agilent Technologies>Software Verification Tool). This will let you know whether there are any missing or potentially corrupted files in your OLCDS ChemStation installation.
2) You can run a repair from disk 1. Make sure you are an administrator in Windows and then right-click on the setup.bat file on disk and select to 'Run as an Administrator'. This will launch the Master Installer where you can find the repair option in the Maintenance tab.
3) If all else fails, uninstall and reinstall the software.