ERROR HRESULT
0x80004005
E_FAIL — generic 'something went wrong'
in plain english
The most useless of useful error codes. E_FAIL is 'unspecified error' — it tells you a COM/Win32 call failed but not why. The cause is somewhere in the calling component's logs (Outlook OST, network share, COM activation, COM automation, Hyper-V, MSI). Treat this code as a starting point, not an answer.
most likely causes
- Outlook: OST/PST corruption or a SharePoint/share with broken auth
- Network share: SMB signing mismatch, NTLM blocked, or Kerberos delegation failure
- COM/DCOM: activation permission denied, server unreachable, or port blocked
- Hyper-V: VM config mismatch, integration services missing, or storage driver fault
- MSI installs: a custom action returned the wrong code or a prerequisite isn't installed
fix path
- Find the component that raised it: Event Viewer → Application + System logs filtered to the time of the error
- For Outlook: scanpst.exe on the OST/PST, or recreate the profile
- For COM: Component Services (dcomcnfg) → check launch/access permissions on the failing CLSID
- For network shares: \\server\share over UNC vs DNS name, capture an SMB trace if reproducible
- Always pair this code with the calling component's own log — Outlook ETL, Hyper-V Worker log, MSI verbose log, etc.
seen in
Outlook send/receive · Network share access · COM/DCOM activation · Hyper-V VM start · MSI installer custom actions
related
verified