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WINDOWS · 0x0000000B ERROR_BAD_FORMAT

How to fix Windows error 0x0000000B

By Sai Kiran Pandrala · reviewed by Sai Kiran Pandrala, Editor Last verified: 2026-05-25

⚡ At a glance
Error code0x0000000B
Decimal11
Symbolic nameERROR_BAD_FORMAT
PlatformWindows
Official messageAn attempt was made to load a program with an incorrect format.
SourceMicrosoft Win32 system error codes

What is 0x0000000B?

Real-world context. Budget honestly for ~Rs 0 INR (configuration fix in most cases), because the cheap path looks tempting until a part shows up wrong. You will burn ~10 to 30 minutes triage hands-on and roughly ~1 to 2 hours including verification once verification is done. Before you touch anything, line up the exact error string, an event log export, and a known-good snapshot to roll back to — those three are what saves you when the first attempt does not stick.

0x0000000B is a Windows system error code that bubbles up from a Win32 system call. The symbolic name ERROR_BAD_FORMAT belongs to a Win32 system call, so when you see it the failure is almost always related to that area, not the app that happens to print the message. In plain English: the system is reporting that an attempt was made to load a program with an incorrect format.

Application logs treat 0x0000000B as opaque, which is why the fix usually involves dropping one layer down: check the underlying API call, the OS resource it touched, and the permissions or state at the moment of the call. The original message is short on context for a reason. The kernel returns the code; the friendly text is up to whichever shell or app surfaces it.

When does 0x0000000B appear?

0x0000000B shows up in a handful of recurring situations. Knowing which one you are in saves you from random chair-spinning. Walk through the list below and tick off the scenario that matches what you were doing when the error landed.

How serious is 0x0000000B?

Severity: Medium. On its own this is not a danger sign, it is a configuration or permissions signal. Treat it as a hint about what to check rather than a reason to panic. The error code itself is just a status return, the real question is what the caller was trying to do at the moment it fired. Always pair the code with the timestamp and the surrounding event log entries before deciding what to repair.

How to fix 0x0000000B

Detect the failure (PowerShell, run as Administrator)

# Confirm that 0x0000000B is what you are looking at.
$errCode = [int]11
[System.ComponentModel.Win32Exception]::new($errCode).Message

# Pull recent system + application errors that match this code.
Get-WinEvent -FilterHashtable @{LogName='System'; Level=1,2,3; StartTime=(Get-Date).AddHours(-24)} -MaxEvents 200 |
  Where-Object { $_.Message -match '0x0000000B' -or $_.Message -match 'ERROR_BAD_FORMAT' } |
  Select-Object TimeCreated, Id, ProviderName, Message | Format-List

Fix: generic Windows error triage

# 1. Decode the error code into its plain-English description.
net helpmsg 11

# 2. Pull recent failures from the System and Application logs.
Get-WinEvent -LogName System -MaxEvents 50 |
  Where-Object { $_.LevelDisplayName -in 'Error','Critical' } |
  Select-Object TimeCreated, Id, ProviderName, Message | Format-List

# 3. Run the in-box integrity tools.
sfc /scannow
DISM /Online /Cleanup-Image /RestoreHealth

Verify the fix

# 1. Re-trigger the original operation and confirm no new event lands.
$before = Get-Date
# (run the previously failing command here)
Get-WinEvent -LogName System -MaxEvents 50 |
  Where-Object { $_.TimeCreated -ge $before -and $_.Message -match '0x0000000B' }

# 2. Decode the error code one more time to confirm it is gone.
net helpmsg 11

Short-term workarounds for 0x0000000B

If you cannot fix the root cause right now, these reduce the impact without papering over the real issue:

Quick verify checklist for 0x0000000B

Frequently asked questions

What does 0x0000000B mean exactly?

The system is reporting that an attempt was made to load a program with an incorrect format.

Is 0x0000000B dangerous?

By itself this surfaces as a warning, not a critical failure. It surfaces as a status line, not an attack indicator. What matters is the failure it points to: a denied permission, a missing module, or a resource limit you crossed. Repair the underlying cause and the code stops appearing.

Will reinstalling fix 0x0000000B?

Treat it as a last resort. Most occurrences of this code resolve with a permission fix, a registry edit, or a driver rollback long before a reinstall becomes useful. Reach for the install media only after the in-box repair stack and a chkdsk pass both come back clean.

How is 0x0000000B different from 0x80070005?

Same neighbourhood, different owners. 0x0000000B came from the path you are debugging, while other codes in the range come from their own services and need their own fixes. Confirm the exact code before assuming the steps overlap.

How do I find out which process is throwing 0x0000000B?

Start with Event Viewer. Filter the System and Application logs by the time you saw 0x0000000b, then look at ProviderName and ProcessId. From an elevated PowerShell prompt, Get-WinEvent with a filter on those fields and a Message -like '*0x0000000b*' clause narrows it down to the exact emitter.

Codes that sit in neighbouring corners of the same subsystem. Worth a glance if the fix above did not land:

Related guides worth a look while you sort this one out:

References

Field notes from real Windows incidents

When I work on the 0x0000000B symptom the rhythm I lean on is the one I have built over years of these tickets. Windows error codes come in a handful of families; once you recognise the family, the doc page is one search away. DISM RestoreHealth needs network or a known-good source image; the most common cause of a failed RestoreHealth is a blocked Windows Update endpoint. Reliability Monitor is the single most underused triage surface in Windows — it gives 30 days of crash history without writing a query.

Tools I actually reach for

For the 0x0000000B symptom on Windows the cheapest signal I can land usually comes from DISM and sfc, then Windows Performance Recorder, Process Monitor (procmon), PowerShell Get-WinEvent when DISM and sfc cannot see the layer the fault sits in, and WinDbg for STOP code analysis for the cases where neither of those answers cleanly. That ordering is not academic. It matches the layers the failure tends to surface through, so the cheap signal lands first and the heavier tooling only comes out when the simpler answer does not hold up under scrutiny.

Verification I run before I close the ticket

Before I mark the 0x0000000B symptom resolved on a Windows unit, the verification loop below is what I actually run. Each step proves a different layer is green, and the order matters - the cheap checks gate the more expensive ones.

wevtutil epl System system.evtx  # export for offline review

If that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.

Get-WinEvent -FilterHashtable @{LogName='System'; Level=1,2; StartTime=(Get-Date).AddDays(-7)}

If that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.

sfc /scannow

If that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.

DISM /Online /Cleanup-Image /RestoreHealth

Only when every line above runs clean do I close the ticket and update the runbook with the timestamps.

Where I check first when the docs disagree

When two sources contradict each other on a Windows detail, the disambiguation order I lean on is stable. I usually start at learn.microsoft.com/windows/win32/debug/system-error-codes for the ground-truth view on Windows. I usually start at techcommunity.microsoft.com/category/windows for the ground-truth view on Windows. I usually start at github.com/microsoft/Windows-Driver-Frameworks for the ground-truth view on Windows. Random blog posts and reseller wikis are signal, not ground truth, and I treat them as such until the references above either confirm or contradict the claim.

Pitfalls I have walked into on this exact path

The shortcuts that look smart on the 0x0000000B symptom have a habit of biting back. The pitfalls below are the ones I have personally walked into on a Windows unit, not things I read about. DISM RestoreHealth needs network or a known-good source image; the most common cause of a failed RestoreHealth is a blocked Windows Update endpoint. STOP codes look terrifying but the first DWORD almost always points directly at the responsible driver. When in doubt I revert to the slower path that the manual prescribes - the time I save by skipping it is always smaller than the time I spend cleaning up afterwards.

What I tell the next on-call

When I hand the 0x0000000B symptom off to the next person on rotation, the three lines I leave in the runbook are these. First, the symptom signature for Windows on the Windows family - not a paraphrase, the exact string that surfaces. Second, the diagnostic that gave the highest signal in the least time. Third, the exact verification command whose green output justified closing the ticket. That trio is what turns a one-off fix into a runbook entry the next engineer can use without paging me at three in the morning.

I also add a one-line note on the cost of getting this wrong. For the 0x0000000B symptom on a Windows unit, the cost is rarely the replacement part. It is the downtime, the second site visit, and the trust deficit you spend with whoever owns the asset when the fix does not hold. That framing keeps the next on-call from choosing the cheap-looking shortcut that ends up costing the most in elapsed hours and goodwill.