What are Outlook Data File Errors?
Outlook stores mail in two kinds of local files. A PST file holds archives and POP mail. An OST file holds an offline copy of an Exchange, Microsoft 365 or IMAP mailbox.
An error appears when Outlook cannot open, save to or trust one of these files. Damage, a wrong setting or a second program using the file can cause it.
Which Error Message do You See?
Match the message on your screen with a row below. Then open the linked guide for the fix.
| Message you see | Likely cause | Guide |
|---|---|---|
| Data file has not been configured | Full or unlinked PST file in the profile | Has not been configured error |
| Data file is already in use | Second profile, program or read only file holds the PST | Already in use in the current profile |
| PST usage is disabled | A policy or registry setting blocks PST files | PST usage is disabled on this computer |
| Errors have been detected in the file .ost | Damaged OST file | Error detected in the OST file |
| Cannot open OST file | OST copied from another computer or profile | Cannot open OST file |
| Error code 0000000E | Damaged OST file | OST error code 0000000E |
| Cannot start Microsoft Outlook | Broken profile or navigation pane | Cannot start Microsoft Outlook |
| Your Outlook data file cannot be configured | Damaged OST or PST file, full disk or broken profile | Data file cannot be configured |
How do You Repair a Damaged PST File?
Method #1: Inbox Repair Tool (Free With Outlook)
Who it suits. Users who see a message that Outlook cannot open the data file or the set of folders. Extra application. None, because SCANPST.EXE installs with Outlook.
- Close Outlook.
- Go to the folder that holds SCANPST.EXE. For Outlook 2016 and 2019 Microsoft lists C:\Program Files (x86)\Microsoft Office\root\Office16.
- Open SCANPST.EXE and select Browse.
- Select the PST file and then select Start.
- Select Repair if the scan finds errors.
- Start Outlook with the profile that uses the repaired file.
Microsoft documents these steps on its support page.
Heads Up. Copy the PST file before you repair it. Repair can drop items it cannot save.
Method #2: Restore a Backup Copy (Free)
Who it suits. Users with a recent copy of the PST file. Extra application. None.
Close Outlook and replace the damaged file with the backup copy. Then open Outlook and check the latest items. The guide to restoring Outlook data from a PST file shows the import route.
Method #3: Repair Software (Paid After Demo)
Who it suits. Users whose file fails in the Inbox Repair Tool. Extra application. A PST repair program.
Repair software scans the damaged file and rebuilds the folders into a new PST file. Read our PST repair tool guide before you choose one, and test the demo on a copy.
What About OST File Errors?
An OST file mirrors a server mailbox, so your mail is safe on the server. Close Outlook, move the damaged OST file to another folder and start Outlook. Outlook builds a new OST file and syncs the mailbox again.
Use an OST converter when the server mailbox is gone and the OST file is your only copy.
How do You Prevent Outlook Data File Errors?
- Close Outlook before you shut down Windows.
- Store PST files on your local drive and not on a network share.
- Copy PST files to another drive every week.
- Archive old mail so one file stays small.
- Scan the folder that holds your data files with antivirus software.
A weekly copy turns every future error into a five minute restore.
Frequently Asked Questions
What is an Outlook Data File?
The file stores your mail, contacts and calendar on your computer. PST and OST are the two types.
How do You Find Which Data File Outlook Uses?
Open Account Settings in Outlook, select the Data Files tab and check the location column. Every file shows its path there.
Can the Inbox Repair Tool Fix OST Files?
Microsoft lists both PST and OST files on its repair page. For an OST file the faster fix is a new file built from the server mailbox.
Why does Outlook Say the Data File is in Use?
Another program, a second profile or a read only setting holds the file. Close other programs and check the file properties.
Will Repair Delete My Emails?
Repair can drop items it cannot save. Copy the PST file first so you can go back.
Can You Open a PST File Without Outlook?
Yes. A PST viewer opens the file without Outlook. Use it to read mail while you fix the profile.
When should You Use Repair Software?
Use it when the Inbox Repair Tool fails or reports a file header it cannot read. Test the demo on a copy first.
Author's Verdict
Start with the message on your screen. The table above sends you to the right fix in one click.
Copy the data file before any repair. That one step protects your mail if a fix fails.
Key Takeaways
- PST files are local. OST files mirror a server mailbox.
- Inbox Repair Tool is the first fix for PST damage.
- Weekly copies let you undo every error.