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Kernel OST Viewer is a free OST viewing utility available for Windows users. The freeware is developed by Kernel Data Recovery to perform quick examination on damaged/healthy Outlook offline storage files (OST) and make them readable without using MS Outlook environment. The viewer can open and read the containing items of the file, like e-mails, attachments, tasks, appointment, notes, etc. within the software interface.

Kernel OST Viewer was launched on September 3, 2010 and since then it is open for free use. It is one of the many useful utilities offered in Kernel free tools for unrestricted download and lifetime use.


Kernel for OST Viewer is a standalone utility to scan and view healthy/corrupt OST files without worrying about the intensity of the corruption. The tool has an advanced feature to intact default properties of original file and maintain complete data integrity of file items. The independently-programmed architecture of the utility enables users to open OST files, regardless of the necessity to install MS Outlook and Exchange Server platforms on the host machine.


The OST Viewer has neat and self-descriptive Graphical User Interface, to offer simplified and secured working environment for administrators and users from non-technical backgrounds. The interface embeds an instant search functionality to extend the overall speed and performance of the process for locating the OST file. The search feature is handy at times when the precise location of the file is unknown to the user. The utility also features the option to open single file/multiple files at once and display them in a single cycle to promote flexible working.


Open corrupt File

The utility can open OST files, when in state of severe corruption or throwing any type of error, caused from different reasons like data storage device failure, power failure, networking connection failure, incorrect file system recovery, virus attacks, synchronization troubles etc.

View Password-Protected File

Kernel OST Viewer uses unique programming technology to open and view encrypted OST files (password-protected) without necessarily having the password.

View Deleted items & Attachments

The software facilitates a preview pane for the users to view the total list of items contained in OST files. The recovered items are separated in different folders depending upon the category of components like inbox, deleted items, calendar, schedules, address book, tasks, journals, etc.

The view of items is represented in a tree-like structure to maintain simplified user readability. The deleted items are retrieved and marked in red color to give quick and easy identification to the viewer. The option to open email messages with attachments is also permitted to the user within the tool.

Customized View Settings

The OST file items can be viewed using any of the two preview tabs: Simple View and Advanced Properties View. The Advanced Properties View supports the different viewing options like Hex preview, Txt preview and Unicode Txt preview. It also gives the flexibility to customize the view according to the end-user by arranging them on the basis of different sorting fields like from, subject, date/time etc.

Filter Items

Find any specific emails or items by defining the search criteria from the available filters (like from, to, subject, received before/after, and message has attachments). The find option quickly segregates the list of items falling in the defined parameters.

Copy & Print Support

The OST Viewer is also enrooted with feature to easily perform copy and print of HTML and TXT pages.

File Analysis Report

Generate and view a customized file analysis report of the file items using the inbuilt four fields like Total Item Types, Mail Flow Density by Date, Mail Flow Density by Sender and Interaction between Users.


Kernel OST Viewer is completely free to download and use. To get more detailed information on License, visit the official website.

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