Old Outlook mail usually lives in a .pst file under the old user’s Documents\Outlook Files folder on Windows 10 and 11, in the hidden AppData\Local\Microsoft\Outlook folder if the file was created by Outlook 2007 or earlier, or under Documents and Settings on much older Windows. If it is not there, search the whole drive for *.pst with hidden items shown. Once you find it, PstVault, a Windows app from Automata Labs, opens the PST read-only without Outlook, so you can search it and export the messages you need as PDF, EML or HTML.
This guide covers where to look, how to search a drive or backup, how to pick the right file when you find several, and what to do if all you find is an OST.
Open the PST you found and export what you need, without Outlook.
Get it from Microsoft
Will there even be a PST file?
It depends on the kind of email account the old PC used. Microsoft’s support page on finding and transferring Outlook data files puts it this way:
- POP accounts: “all of your information is already stored in a Personal Folders (.pst) file.” This is the classic case for an old home or small-office PC.
- Microsoft 365, Exchange or Outlook.com accounts not accessed by POP or IMAP: “you won’t have a Personal Folders (.pst) file.” You may have an Offline Folders (.ost) file, which Outlook recreates, and the mail itself is on the server.
There is a third case: anyone can export or archive mail to a PST by hand. Those files can be anywhere, which is why a drive-wide search is worth doing even if the account was Microsoft 365.
Where did Outlook keep PST files?
Microsoft lists these locations for POP account data files, plus the older default for files made by Outlook 2007 and earlier:
| Windows version | Folder |
|---|---|
| Windows 10 and Windows 11 | drive:\Users\username\Documents\Outlook Files |
| Windows Vista and later, PST created by Outlook 2007 or earlier | drive:\Users\username\AppData\Local\Microsoft\Outlook (hidden) |
| Older versions of Windows | drive:\Documents and Settings\username\Local Settings\Application Data\Microsoft\Outlook |
The AppData row matters more than it looks. Outlook 2007 and earlier saved PST files in this hidden folder on Windows Vista and later, and Microsoft’s page on opening an Outlook data file still lists drive:\Users\user\AppData\Local\Microsoft\Outlook\archive.pst as the archive location for earlier versions of Outlook. Files created there are not moved when Outlook is upgraded, so a PC that ran Outlook 2007 and later got a newer version can have mail in both places. The same folder also holds .ost cache files, so check the extension before you copy anything.
On an old drive connected to a new PC, “drive” is the letter Windows gave it, such as E:, and “username” is the old account name. Microsoft’s data file transfer page notes that some of these folders may be hidden and that Windows may hide file name extensions such as .pst and .ost, so turn both on in File Explorer under View, then Show.
If the old account used OneDrive to back up Documents, also check the OneDrive folder in that profile, and the OneDrive website if you still have the account.
How do I search a whole drive or backup for PST files?
With File Explorer. Open the drive or backup folder, type *.pst in the search box, and wait for the search to finish. Add the Size and Date modified columns. Searching an unindexed external drive can be slow, so give it time.
With PowerShell, which is faster on large drives and lists everything in one table:
Get-ChildItem E:\ -Recurse -Filter *.pst -ErrorAction SilentlyContinue |
Select-Object FullName, Length, LastWriteTime |
Sort-Object LastWriteTime -DescendingChange E:\ to the drive or backup folder. The -ErrorAction SilentlyContinue part skips folders you are not allowed to read rather than stopping. Run it again with *.ost to see what offline caches exist.
In backups. A PST inside a zip, a backup program’s archive or a disk image will not show up until you restore or mount that backup. Restore to a new folder, not over anything.
Which PST is the one I want?
You may find several. Sort them out by:
| Clue | What it suggests |
|---|---|
| Largest file, most recent date | Probably the main mailbox file for a POP account |
| A name like the email address | Usually created by Outlook for that account |
| A name someone typed, such as “2019 mail” | A manual export or archive |
| Very small file | Often an empty or nearly empty data file |
| Same name in several places | Copies; compare sizes and dates and keep the newest |
Copy the candidates to your current PC before opening them, and leave the originals on the old drive untouched.
Check each PST you found in minutes and keep the one that holds the mail.
Get it from Microsoft
How do I look inside without Outlook?
- Open PstVault and choose the PST. It opens read-only. The original stays unchanged.
- Browse the folders. You will see quickly whether this is the main mailbox, an old archive, or nearly empty.
- Search. Narrow by sender, recipient, subject, words in the message body, or date.
- Export what you need. PDF for reading, printing or sharing, as individual files or one bookmarked PDF; EML for other mail apps; HTML for offline reading copies. Contacts export to CSV or vCard, and supported calendar events to ICS.
- Save attachments as separate files if you need the originals.
- Read the export report, which lists complete, partial, failed and unprocessed items.
Our guide to opening a PST file without Outlook covers this in more depth, and how to export emails from a PST file walks through the export choices.
What if the file will not open?
- It is an OST. PstVault does not open OST files. If the account was Microsoft 365, Exchange or Outlook.com, the mail is normally still on the server; sign in to the account instead.
- It is an ANSI PST. PstVault is designed for readable Unicode PST files and does not claim support for the older ANSI format.
- It is damaged or encrypted. PstVault does not repair damaged archives or decrypt encrypted messages.
- It is not really a PST. Our post on the PST “is not an Outlook data file” error explains how to tell.
What should I do before wiping the old drive?
Old drives get recycled with mail still on them. Before you wipe, sell or recycle one:
- Run the PowerShell search above and save the list it prints.
- Copy every PST in the list to your current PC or a backup drive, even ones that look unimportant.
- Open each copy and confirm it holds what you expect.
- Export anything you will need to share or keep long term, such as tax or legal correspondence, to PDF.
- Only then wipe the drive.
A PST copied to a USB stick is easy to lose, so keep at least two copies of anything that matters.
Frequently asked questions
Can I just copy the PST to my new PC?
Yes. Microsoft’s page says you can move a PST to a new computer and keep your information, but moving it doesn’t transfer account settings. To read it, you can open it in Outlook or in a viewer like PstVault.
Is it safe to open a PST from someone else’s old PC?
Open a copy, and only if you are entitled to the mail. For a former employee’s mailbox, see our IT guide to a departed employee’s PST.
Does PstVault upload my email?
No. Mail processing happens on your PC and PstVault does not connect to a mail server.
What is a PST file, exactly?
An Outlook data file that stores a copy of a mailbox. Our explainer on what a PST file is covers the details.
Try PstVault
PstVault is a one-time purchase in the Microsoft Store with a free trial, so you can open the PST you found and see what is inside before you buy. More detail is on the PstVault product page.
Turn an old PST from a forgotten drive into files you can use today.
Get it from Microsoft
Outlook is a trademark of Microsoft. PstVault is not affiliated with Microsoft.
Last updated 22 October 2026. Published by Automata Labs, a software company in Canada.