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OST files are tied to your MS Outlook account and Windows profile and are not independent data files like PST files. If you copy an OST file directly to a new PC, Outlook usually ignores the copy or directly creates a brand-new OST during account setup. It then syncs mailbox data from the server and stores it in the newly created local cache file in the new system.

A proper strategy is essential if you want to transfer your OST file to a new computer without losing emails, contacts, or calendars. Since the OST files are specific to individual profiles, they can either duplicate themselves or corrupt themselves. In this guide, we will look into the situation so that you don’t accidentally lose important mailbox content during the transfer process.

Things to Check Before You Transfer OST File to New Computer

It is very important to review factors that can directly affect the migration process.

• There are few folders inside the OST named “This Computer Only”. These files do not exist on the server or might have been created when you were offline. Exporting them becomes necessary if you want them on the new machine.
• If the mailbox increases in size, it gets tough to transfer or even sync from the server in the new machine.
• Backup is always necessary for any kind of migration. You have to convert the OST files into other formats (like PST), because OST cannot be directly backed up.

Checking these points in advance will help ensure smooth and proper transfer of OST data to the new computer without any issues.

Where Is the OST File Stored?

Before transferring the OST file safely, you need to know where it is actually stored. Outlook normally saves OST files in its default location unless you’ve moved them before.

If you’ve changed the OST file location and don’t remember it, follow these steps:

• Open Outlook.
• In Account Settings, go to File.
• Under Data Files tab, select your account.
• Click Open File Location.
• This opens the folder where your OST file is located.

Generally, you’ll find the folder containing your OST file here:

C:\Users\YourUsername\AppData\Local\Microsoft\Outlook

Reliable Ways to Transfer OST File to New Computer Without Data Loss

If you are trying to transfer OST file, select the right approach so you can avoid profile conflicts or missing important data. Since OST files are profile-bound, they cannot be used on a new PC via direct copying method, unless you have your account’s credentials.

Here are 2 manual methods and 1 advanced solution listed to transfer OST files safely:

#1 Account Configuration/IMAP Re-Sync

By adding the same account to the new computer, MS Outlook recreates the OST and automatically syncs mailbox data.

Steps:

• Install MS Outlook and launch it on the new machine.
• Add pre-existing email account using valid credentials.
• Allow Outlook to complete its steps and create a new set of OST files.
• After the last step, Outlook will sync all the data from the old computer to the new PC.

Pros:

• Easy, simple, safe, and built-in approach.
• Restores server-based mailbox data automatically.
• No need for copying OST files one-by-one.

#2 Access Mailbox Through Web Interface

If your mailbox data is stored on the server, you can access it through the web interface before configuring Outlook on the new computer. This helps confirm that emails, contacts, and calendars are available online and ready for sync.

Steps:

• Sign in using a web browser.
• Verify that mailbox and recent emails are visible.
• Contacts and Calendar are also visible.
• Proceed with Outlook setup on the new computer.

Pros:

• Quick way to verify server-side data availability.
• Verify whether your last changed email is synced or not.
• Helps prevent unnecessary data transfer attempts.

Disadvantages of Manual Methods

• Both methods depend on active server access and valid account credentials.
• Folders marked as “This Computer Only” cannot be restored through sync or web access.
• Large mailboxes may take a long time to download on the new computer during re-sync.
• Ineffective if the Outlook profile is corrupted or the account is unavailable.
• The process involves multiple steps and verification stages, making it slower than automated migration solutions.

#3 Using Automated OST Converter Tool

OST files cannot be directly transferred by copy-pasting because they are linked to the Outlook profile and system. To preserve mailbox data safely, OST files must be backed up and converted into a portable format like PST, enabling secure transfer.

Automated solutions like SysTools OST to PST converter allow direct access to OST files without requiring Outlook configuration or server sync. This is helpful for large or partially synced OST files where attachments may take significant time to download or certain items may not exist on the server. Using a professional conversion method ensures complete mailbox extraction without data loss.

Steps:

• Close Outlook on the system.
• Launch the installed software.
• Select the target OST file or folder.
• Choose the preferred output format (PST) and destination path.
• After completion, access the exported data on the new computer.

Benefits of Using an Advanced Tool:

• Creates a proper PST backup before migration.
• Keeps emails accessible even if the OST becomes inaccessible.
• Protects data if the account is removed or disabled.
• Reduces risk when moving OST files to another computer or drive.
• Provides better control compared to relying solely on Outlook sync.
• Provides a strong PST backup that eliminates dependence on the OST format.

Let’s Recap!

We have covered different methods to transfer OST files to a new computer, including detailed steps of manual and professional solutions. You can pick the most appropriate method, but creating a PST backup using professional software is the quickest approach and ensures safety of your mailbox data.