In Office 365, which uses the Click-to-Run technology, Office program files are now in a new location.
When you experience issues with Outlook, often you would use the ScanPST.exe tool to repair PST and OST files with Outlook.
This tool can now be found in the following location:
C:Program FilesMicrosoft Office 15rootoffice15ScanPST.exe
Update:
Microsoft has published a Knowledge Base article list the locations of the ScanPST utility depending on your installation of Office 365. Whether you’re using 32 or 64 bit versions.