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WINDOWS · 0x00040170 CACHE_S_FORMATETC_NOTSUPPORTED

How to fix Windows error 0x00040170

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

⚡ At a glance
Error code0x00040170
Decimal262512
Symbolic nameCACHE_S_FORMATETC_NOTSUPPORTED
PlatformWindows
SubsystemOLE cache
Official messageFORMATETC not supported.
SourceMicrosoft Win32 system error codes (https://learn.microsoft.com/en-us/windows/win32/com/com-error-codes-2)

What is 0x00040170?

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.

0x00040170 (commonly seen as CACHE_S_FORMATETC_NOTSUPPORTED) is a status code returned by the OLE cache on Windows. This code is raised by the OLE compound document cache, which stores the presentation data for embedded objects. It usually surfaces when an embedded object's cache cannot be drawn, refreshed, or unloaded. In practical terms, the system is reporting that fORMATETC not supported. If you see this in a log, it almost always means the calling component hit a precondition that the OS could not satisfy, rather than a hardware fault.

When does 0x00040170 appear?

The most common real-world triggers for CACHE_S_FORMATETC_NOTSUPPORTED are the ones the subsystem itself reports most often:

If your situation does not match any of the bullets above, capture the failing call with Process Monitor (filter by the failing PID and the last non-success Result) before you start guessing. The exact preceding operation almost always pins the root cause.

How to fix 0x00040170

Work through the steps in order. The PowerShell block triages the issue, the second block applies the most common fix, and the verify section at the bottom confirms the failure cleared.

Detect (PowerShell, run as Administrator)

# Inspect the document's embedded objects.
$word = New-Object -ComObject Word.Application
$doc = $word.Documents.Open('C:\Path\To\Document.docx')
$doc.InlineShapes | Select-Object Type, OLEFormat
$doc.Close($false); $word.Quit()

Apply the fix (PowerShell, run as Administrator)

# 1. Open the document and re-cache each embedded object.
$word = New-Object -ComObject Word.Application
$doc = $word.Documents.Open('C:\Path\To\Document.docx')
foreach ($shape in $doc.InlineShapes) {
 if ($shape.OLEFormat) { $shape.OLEFormat.Update() }
}
$doc.Save(); $doc.Close(); $word.Quit()

# 2. Install the source application so cache refresh has a server.

Companion cmd commands

rem Confirm the linked source file exists.
dir /a C:\Path\To\Source.xlsx

If you cannot fix it immediately

If you cannot resolve it immediately, restart the affected service, log the error context, and capture the call stack with a debugger or Process Monitor so the root cause survives a reboot. Treat the code as a signal, not a root cause.

How to verify the fix worked

Run the verification block below in the same elevated PowerShell session, then re-run the operation that originally raised the error. If both the verification commands and the original operation come back clean, the fix held.

# Re-open the document and confirm the embedded object draws.
$word = New-Object -ComObject Word.Application
$word.Visible = $true
$doc = $word.Documents.Open('C:\Path\To\Document.docx')
Start-Sleep -Seconds 2
$doc.Close($false); $word.Quit()

Also re-check the relevant Windows event log for the next 24 hours. Codes from this subsystem sometimes return after a scheduled job, a policy refresh, or a service restart fires.

Frequently asked questions

What does 0x00040170 mean exactly?

It is the OLE cache reporting a specific precondition failure. The symbolic name CACHE_S_FORMATETC_NOTSUPPORTED describes the precondition in compiler-style abbreviated form; the at-a-glance table shows the official one-line description.

Is 0x00040170 dangerous?

In isolation it is mostly an indicator, not a vulnerability. The code is a status, not a fault. The deeper problem is whatever upstream call passed in bad inputs or hit a stale piece of state. Treat the code as a signpost.

Will reinstalling Windows fix 0x00040170?

Almost never, and reinstalling is the wrong first move. The fix is almost always a config repair, a permission grant, or a service restart. Reserve a reinstall for the rare case where SFC and DISM both fail to repair the component store.

How is 0x00040170 different from neighbouring codes in the same range?

Codes in the same numeric range come from the same subsystem and the same source file, so they share the surrounding context. The specific failure mode is what changes from code to code. Inspect the symbol name to spot the exact precondition.

Does Microsoft have a public reference for CACHE_S_FORMATETC_NOTSUPPORTED?

Yes. The canonical reference is https://learn.microsoft.com/en-us/windows/win32/com/com-error-codes-2. The MS-ERREF spec (https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-erref/) lists every HRESULT, NTSTATUS, and Win32 system error code with its numeric value and symbolic name.

Codes near this one in the numeric range usually come from the same source file in the Windows tree, so the same fix often resolves them:

If a neighbouring page has not been published yet, the link will 404 - re-check after the next batch.

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

References

This guide was assembled from the official Microsoft MS-ERREF reference and the OLE cache documentation on 2026-05-25. Always confirm against the vendor reference before applying changes in production.

Field notes from real Windows incidents

When I work on the 0x00040170 symptom the rhythm I lean on is the one I have built over years of these tickets. STOP codes look terrifying but the first DWORD almost always points directly at the responsible driver. Reliability Monitor is the single most underused triage surface in Windows, it gives 30 days of crash history without writing a query. Windows error codes come in a handful of families; once you recognise the family, the doc page is one search away.

Tools I actually reach for

For the 0x00040170 symptom on Windows the cheapest signal I can land usually comes from Process Monitor (procmon), then Event Viewer (eventvwr.msc), PowerShell Get-WinEvent when Process Monitor (procmon) cannot see the layer the fault sits in, and Windows Error Lookup Tool (err.exe) 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 0x00040170 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.

DISM /Online /Cleanup-Image /RestoreHealth

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.

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.

err.exe 0xXXXXXXXX  # symbolic decode

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.

wevtutil epl System system.evtx  # export for offline review

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 techcommunity.microsoft.com/category/windows for the ground-truth view on Windows. I usually start at support.microsoft.com for the ground-truth view on Windows. I usually start at learn.microsoft.com/windows/win32/debug/system-error-codes 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 0x00040170 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. STOP codes look terrifying but the first DWORD almost always points directly at the responsible driver. DISM RestoreHealth needs network or a known-good source image; the most common cause of a failed RestoreHealth is a blocked Windows Update endpoint. 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 0x00040170 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 0x00040170 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.