What you’re seeing
- Outlook closes immediately with the message 'Cannot start Microsoft Outlook. The set of folders cannot be opened.'
- A variation reads 'Cannot open the Outlook window' or says the information store could not be opened.
- The error appears every time Outlook starts, even after a reboot.
- Webmail works for the same account, confirming the mailbox itself is fine.
Common causes
Every environment is different, but these are the causes our engineers find most often:
- The PST or OST data file Outlook expects has been moved, renamed, deleted or locked by another program.
- A data file stored on a network share, USB drive or OneDrive-synced folder became unavailable or damaged.
- The Outlook profile or the navigation pane settings file is corrupted.
- The PST file has grown past a practical size or picked up file-level corruption after a crash or forced shutdown.
- Outlook is set to run in compatibility mode or as a different user, so it can't reach the profile's files.
Why it matters
This error blocks Outlook completely on the affected PC, so the user can't send quotes, read customer messages or manage their calendar from the tool they know. For staff who keep years of client history in local PST files, the error also raises fears of permanent data loss. Hasty fixes like deleting files can turn that fear into reality. Getting Outlook open again quickly, with the data intact, keeps the user working and protects records.
How AskTechGurus fixes it
Skip the trial and error. A certified engineer works on your actual system, finds the root cause, and fixes it properly.
Tell us what’s happening
Submit a ticket in about two minutes. Paste the error, describe what changed, and pick your tier. No charge to submit.
A certified engineer diagnoses it
A vetted, US-based systems engineer claims your ticket, usually within minutes during business hours, and investigates over a secure remote session you can watch and end at any time.
Fixed and verified with you
The engineer resolves the root cause and confirms with you that it’s working. You don’t just get a workaround, and you get a plain-English summary of what was wrong.
Pay only when it’s resolved
Fixed price from $99, invoiced only after you approve the fix. If it isn’t resolved, you don’t pay.
Frequently asked questions
Does this error mean our email is corrupted?
Usually it's the local profile or data file on the PC that's damaged, not the mailbox in the cloud. Local PST archives are the part that needs careful handling.
Should we delete the Outlook data file?
Not without knowing what it contains. A PST can hold mail that exists nowhere else, so it should be backed up and examined first.
Can AskTechGurus fix it remotely?
Yes. A certified US engineer works on it through a remote secure session, from $99, and you pay only when it's resolved.