Convert Microsoft Outlook OST to PST when OST Failed to Load

“I have carried some tasks on my Outlook OST file and upon completion, I moved forward to synchronize the changes to Microsoft Exchange server. However, before I could synchronize, my laptop got shut down due to software malfunction. Now, OST file fails to load and shows a message which exactly reads like ‘Failed to load OST file’. My friend has suggested me to run OST integrity tool. I ran that also but same issue is repeating. How can I resolve it?”

Like PST, OST is also a type of storage file in Microsoft Outlook that facilitate users to save emails, contacts, calendars, tasks, notes RSS feeds etc. One of the big advantage of this file is, it allows users to access information even when they are not connected to Microsoft Exchange server. However, when OST file fails to load, it becomes quite nuisance for the users as they lose access to entire information stored in OST file. But sometimes you can pinpoint the cause and solve it using built in procedure. Though manual method helps to resolve your problem in certain case, the issue still remains stable when OST file is corrupted.

Reasons why OST fails to load:

  • External Threats:If you get any spam email with an attachment then you should delete it right away without keeping on Outlook. If you open the mail and download the attachment then OST file might get damaged due to the viruses present in that mail
  • Improper synchronization:In case OST file synchronization is failed due to slow internet connection or unpredicted system shut down then Outlook will not load the contents of OST file
  • Forceful system shut down:Before shutting down your computer, you should click on the small arrow mark provided at the right corner of your Windows computer’s task bar and check whether any file is open from background. If you do not check it then Windows will intimate you about it before turning off. Ignoring the message will cause OST file to get corrupted leaving it in non-accessible state
  • Quitting OST improperly:Header is the important part which stores entire details of OST file. So if you don’t want to damage OST file header, then you should safely close Outlook using “Exit” option. Failing to use suitable option will damage header and it refuse to load its content

Conversion of OST to PST after OST fails to load:

Microsoft Outlook has provided built in way to convert OST to PST file. But this method helps only when OST file is healthy without any errors. If you wish to convert OST file which fails to load then you need to take help from appropriate conversion software. In this matter you can consider Yodot OST to PST Converter software which deals with any errors related to OST file corruption and converts it to a healthy PST file. Users can fix OST error unable to expand the folder, OST file cannot be accessed, OST file is corrupted and cannot be opened error, OST file is not valid error, failed to open OST file error, cannot open default email folder and so on. If you have encrypted OST file and failed to open it due to corruption issue then this software can even fix it and show its preview. Furthermore you can regain access to Outlook OST attributes like contacts, notes emails, calendars, tasks etc. You can restore entire information from a specific attribute; for example you can retrieve entire message body along with subject, CC, BCC and recipient details. Make use of the application on your Windows 8.1, Windows 7, Windows XP, Windows Vista, Windows server 2003 and 2008 operating systems.

Simple procedure to fix OST file which failed to load:

  • Download Yodot OST to PST Converter software and install it on your Windows software
  • Next, run this utility as per given instructions
  • Execute the software by double clicking on the shortcut created automatically on your desktop
  • Once you run the application, you will find two options which are “Open OST File” and “Find OST File”
  • Select first option if you are aware of OST file location otherwise select second one to find it
  • Choose the destination location where you want to save converted OST file
  • Hit on “Convert” option and let the application to scan and convert required OST file
  • Once the conversion process is done, you can view recovered attributes from converted OST file


  • Close OST file before starting OST to PST conversion process
  • Backup Outlook OST file as it may get corrupted at any point making its entire content inaccessible