{"id":148802,"date":"2023-09-13T05:31:38","date_gmt":"2023-09-13T05:31:38","guid":{"rendered":"https:\/\/www.stellarinfo.com\/blog\/?p=148802"},"modified":"2025-06-25T10:06:44","modified_gmt":"2025-06-25T10:06:44","slug":"how-to-attach-an-ost-file-to-a-new-profile","status":"publish","type":"post","link":"https:\/\/www.stellarinfo.com\/blog\/how-to-attach-an-ost-file-to-a-new-profile\/","title":{"rendered":"How to Attach an OST File to a New Profile?"},"content":{"rendered":"

MS Outlook stores your emails, attachments, notes, contacts, and other mail items in an Outlook data file, called Offline Storage Table or OST (also referred to as Offline Folder file). The OST file allows you to have access to all your emails, contacts, and other mail items, even when you are not connected to the internet. However, there are times when your OST file becomes orphaned or inaccessible — either due to a system upgrade or when switching to a different email client — requiring you to attach your OST file to a new profile to have access to your emails.<\/p>

Can I Attach the OST File to a New Profile?<\/h2>

To know the answer, you must first understand what OST file is and how it works.<\/p>

OST file is an offline copy of your mailbox data stored on your computer. It is created as soon as you configure an IMAP, Exchange, Microsoft 365, or Outlook.com account in Cached Exchange Mode<\/a> (default mode).<\/p>

The primary purpose of OST file is to allow users to access their mailbox data even when they are not connected to the internet or mailbox server.<\/p>

The file is also encrypted by default with a MAPIEntryID GUID<\/strong> key that prevents Outlook users from opening, accessing, or importing it in other Outlook accounts, profiles, or systems. Also, you cannot attach an orphaned, inaccessible, or orphaned OST file to a new profile.<\/p>

However, you can convert such orphaned OST files to PST format using an OST to PST converter tool<\/a>, such as Stellar Converter for OST<\/strong>. The tool helps extract your mail items from OST and save them in Outlook importable PST file. This will help you access and restore all your mail items.<\/p>

Process to Attach OST File to a New Profile<\/h2>

Here’s the step-by-step process to attach OST file to a new profile.<\/p>

Step 1: Prepare Your System<\/h3>

To begin with, you need to prepare your system. Close all running applications and save all your work. This will help prevent any conflicts or data loss during the OST attachment process. Also, create a backup of your OST file<\/a>. While the process of attaching the OST file<\/strong> to a new profile is safe, it’s always good to have a backup for just-in-case scenarios. It will help you restore your access to the emails in the OST file.<\/p>

The default location of OST file<\/a> varies based on the Windows edition and Outlook version. However, usually, you will find the OST file at the below location:<\/p>

C:\/Users\/Your_Username\/AppData\/Local\/Microsoft\/Outlook<\/strong><\/code><\/pre>
After finding the OST file, copy the OST file to another location, preferably in another folder or drive.<\/p>
Step 2: Create a New Profile in Outlook<\/h3>
You need to create a new profile where OST will be attached. To set up and create a new profile in Outlook<\/a>, follow these steps:<\/p>