How to fix Outlook error 0x80040600 (PST corruption)
This unknown error means the PST data file is corrupt, so Outlook cannot read or map its data and the export, import or send fails. Repairing the file resolves it. Jump to your situation below or work through the methods in order.
By Neeraj Singh ~7 min Updated Jun 2026 87% found this helpful
Outlook error 0x80040600 is an unknown error caused by corruption in the PST data file. The PST stores your mail, contacts and calendar, and when its internal structure is damaged, often after an improper shutdown, a power loss during sync, or an oversized file, Outlook cannot read or map the data, so export, import and send/receive operations fail. The primary fix is to repair the file with SCANPST, Microsoft's Inbox Repair Tool, after making a backup. If the profile that points to the PST is the problem rather than the file, creating a new Outlook profile resolves it, and recreating the OST helps for cached Exchange or Microsoft 365 accounts. When SCANPST cannot fully repair severe corruption, restoring from a backup or using a dedicated repair tool is the next step. Reducing an oversized file also prevents recurrence.
What this error means
The PST is a database, and 0x80040600 is the generic signal that Outlook could not read or write it because its structure is damaged. The data may still be there, but the file cannot be parsed correctly, so any operation that touches it fails.
Corruption usually traces to an interrupted write, a crash, a power loss mid-sync, or a file that grew too large. SCANPST repairs the structure so Outlook can read it again. When the file is fine but the profile pointing at it is broken, a fresh profile is the fix instead.
Common causes
The PST file structure is corrupt.
An improper shutdown or crash during a write.
A power loss while syncing.
An oversized PST that exceeded safe limits.
A corrupt Outlook profile pointing at the file.
Expert insight
“0x80040600 is Outlook's catch-all for a poorly PST, the file is damaged and it cannot read it. Nine times out of ten the fix is SCANPST, and the one rule I drill into people is back up the PST before you let SCANPST touch it, because the tool edits the file in place. If SCANPST runs clean but the error stays, then it is not the file, it is the profile pointing at it, so I build a fresh Outlook profile and the problem goes away.”
Manager, Tech Support & Operations · 19+ years fixing Windows and system errors
✓ How to fix it
Method 1
Repair the PST with SCANPST
1Close Outlook and run the Inbox Repair Tool SCANPST.EXE from your Office installation folder.
2Browse to the PST file, Start the scan, tick to make a backup, then Repair.
3Reopen Outlook and retry the operation.
Method 2
Back up the PST first
1Before repairing, copy the PST file to a safe location.
2SCANPST edits the file in place, so a backup protects your data.
3Find the path in File, Account Settings, Data Files.
Method 3
Create a new Outlook profile
1If SCANPST runs clean but the error persists, the profile may be corrupt.
2In Control Panel, Mail, create a new profile and add your account.
3Set it as the default and reopen Outlook.
Method 4
Recreate the OST for cached accounts
1For a cached Exchange or Microsoft 365 account, close Outlook and rename the .ost file so Outlook rebuilds it.
2Reopen Outlook to resync.
3This clears OST-side corruption.
Method 5
Use a dedicated repair tool for severe damage
1If SCANPST cannot fully repair the file, restore from a backup.
2For severe corruption with no backup, a dedicated PST repair utility can recover the data.
3Then import the recovered data.
0x80040600 is PST corruption, so repair the file with SCANPST after making a backup, since the tool edits in place. If SCANPST runs clean but the error remains, the Outlook profile is the problem, so create a new one. Recreate the OST for cached accounts, and use a backup or a dedicated tool for severe damage.
Frequently asked questions
What does Outlook error 0x80040600 mean?
It is an unknown error caused by corruption in the PST data file. Outlook cannot read or map the file's structure, so export, import and send/receive operations fail.
How do I fix 0x80040600?
Repair the PST with SCANPST, Microsoft's Inbox Repair Tool, after making a backup. If the error persists with a clean scan, create a new Outlook profile.
Should I back up before SCANPST?
Yes, always. SCANPST edits the PST in place, so copy the file to a safe location first in case the repair does not go cleanly.
Where is SCANPST?
It is in your Office installation folder, for example C:\Program Files\Microsoft Office\root\OfficeXX. Open the Outlook shortcut's file location to find it, then run it as administrator.
SCANPST did not fix it
If SCANPST cannot repair severe corruption, restore the PST from a backup, or use a dedicated PST repair tool to recover the data, then import it into a fresh file.
Could the profile be the issue?
Yes. If SCANPST reports the file is clean but the error remains, the Outlook profile pointing at the PST may be corrupt. Create a new profile in Control Panel, Mail.
Still not working?
If SCANPST repeatedly stops partway or crashes, the corruption is beyond the free tool; restoring from a recent backup is the cleanest path, otherwise a dedicated PST recovery utility can extract the data into a new file. You can also submit your error to us for a tailored fix.
