Verified Recovery Tutorial

How to Convert OST to PST:
Step-by-Step Recovery Guide

Step-by-step walkthrough to extract and convert inaccessible, orphaned, or corrupted Outlook OST files to importable PST format without Outlook or Exchange Server.

1
Locate Outlook Data File

Locate the Outlook OST File on Your Local PC

Before launching the converter, confirm the path of your .ost file. Microsoft Outlook stores cached offline mailboxes in a hidden AppData folder:

%LOCALAPPDATA%\Microsoft\Outlook

Quick Keyboard Shortcut:

1. Press Win + R on your keyboard to open the Run dialog.

2. Paste %LOCALAPPDATA%\Microsoft\Outlook and press Enter.

3. Identify your target mailbox file ending with the .ost extension (e.g. john.doe@company.com.ost).

Important Pro-Tip: If Microsoft Outlook is currently open, close it completely to release file locks on the OST database before scanning.
2
Deep Scan & Ingestion

Open & Deep Scan the Orphaned OST File

Launch WindowsUtils OST to PST Converter (also detailed on the landing page) on your Windows 11 or 10 PC:

Click 'Select OST File' on the home dashboard.
Select either Standard Mode (for normal or orphaned OST files) or Deep Recovery Mode (for severely corrupted or oversized files).
The 64-bit multi-threaded engine parses all internal B-Tree tables, extracting deleted folders, drafts, and attachments automatically.
3
Inspect Mailbox Hierarchy

Preview Mail Items, Contacts, Calendars & Attachments

Once the scan completes, the visual viewer renders the exact folder tree of your mailbox:

Folder Tree Structure

Browse through Inbox, Sent Items, Drafts, Deleted Items, and custom company archives with full item counts.

Email Content & Attachments

Inspect HTML message bodies, sender headers (From, To, CC, Date), and click embedded attachments to verify fidelity.

You can check or uncheck individual folders if you only wish to export specific folders rather than the entire mailbox.

4
Export & Outlook Mount

Export to PST & Open in Microsoft Outlook

Configure your export settings and generate your clean, portable PST container:

Choose PST (Outlook Personal Storage Table) as your target format.
Set your destination folder (e.g. D:\Outlook Archives\).
(Optional) Enable Split PST if your mailbox exceeds 20 GB to ensure optimum Outlook responsiveness.
Click 'Convert Now'. The process runs at high speed with live progress feedback.

Mounting Your Converted PST in Microsoft Outlook

1. Launch Microsoft Outlook (2024, 2021, 2019, 2016, or Microsoft 365).
2. Go to File > Open & Export > Open Outlook Data File.
3. Browse to your newly generated .pst file and click OK.
4. The entire converted folder hierarchy will instantly appear in the left-hand folder pane, ready for searching, forwarding, and replying!

Troubleshooting

Frequently Asked Questions About How It Works

Where does Microsoft Outlook store OST files on Windows?

In Windows 11 and 10, default Outlook OST files are located in C:\Users\<Username>\AppData\Local\Microsoft\Outlook. You can jump directly to this directory by pressing Win + R and typing %LOCALAPPDATA%\Microsoft\Outlook.

Can I convert an OST file without having Outlook installed?

Yes. WindowsUtils OST to PST Converter has a built-in MAPI parsing engine. It runs 100% standalone and reads OST files directly without requiring Outlook, Exchange Server, or Microsoft 365 credentials.

How do I open the converted PST file in Microsoft Outlook?

Open Microsoft Outlook, click File > Open & Export > Open Outlook Data File. Browse to your converted .pst file and click OK. The entire mailbox tree will appear immediately in your Outlook navigation pane.

Will converting OST to PST affect my original OST file?

No. The conversion process is strictly read-only. Your original OST file is never modified, ensuring your existing data remains completely untouched.

Ready to Recover Your Outlook Mailbox in 5 Minutes?

Download WindowsUtils OST to PST Converter and convert inaccessible OST files into healthy, portable PST archives.