Windows Installer
0x80070643
The same fatal install failure as 1603, wrapped as an HRESULT.
Failure
What it means
This is not a separate error. 0x8007 is the Win32 facility prefix, and 0643 is 1603 in hexadecimal, so 0x80070643 is exactly Windows Installer error 1603 delivered through Windows Update, Configuration Manager, or Intune. Anything that fixes 1603 fixes this.
Real causes
- A Windows update package failed during installation and the servicing stack returned the installer's 1603.
- A .NET Framework update failed, which is one of the most common sources of this code in Windows Update.
- The component store is damaged, so the update could not be staged.
What to do
- Treat it as 1603. Get the installer log first, do not guess.
- For a Windows update, check
%windir%\Logs\CBS\CBS.logand search for ", error". - Run DISM.exe /Online /Cleanup-Image /RestoreHealth then Sfc.exe /Scannow, and restart.
- If the failing update is .NET Framework, download the standalone package and install it manually to get a real error message.
Where to look
%windir%\Logs\CBS\CBS.log%windir%\Logs\DISM\dism.log%temp%\dd_*.logfor .NET installers
Checked against Microsoft documentation. Last reviewed 2026-08-20.
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