In plain words
A Windows error code is like a number plate: unreadable as it is, but each part means something. 0x80070005 reads as "failure, from the Win32 family, number 5", and Win32 error number 5 means "access denied". The tool does this reading, then suggests the most likely fixes.
The four families of codes
| Family | Form | Where you see it |
|---|---|---|
| Win32 error | A number: 5, 1603, 0x422 |
Applications, MSI installers, net helpmsg |
| HRESULT | 0x8xxxxxxx |
Windows Update, Microsoft Store, activation, applications |
| NTSTATUS | 0xCxxxxxxx |
Application crashes, startup, security logs (sign-ins) |
| Stop code | 0x0000007B or its name (INACCESSIBLE_BOOT_DEVICE) |
Blue screen |
An HRESULT breaks down into three parts: the severity (the first bit), the code's origin (the "facility": 7 for Win32, 36 for Windows Update, 49 for BitLocker…) and the number. So every 0x8007xxxx code contains a classic Win32 error: 0x80070643 is Windows Installer error 1603.
The official message, on any Windows computer
Outside this tool, certutil /error 0x80070005 shows the official name and message of most codes, and net helpmsg 5 those of Win32 errors. For a blue screen, the C:\Windows\Minidump\*.dmp files can be analysed with WinDbg, available in the Microsoft Store.
The tool's limits
The database covers nearly 200 of the most common codes: frequent Win32 errors, Windows Update and servicing, upgrades, activation, sign-in failures and blue screens. For a code that isn't there, the tool still gives its breakdown and the command that shows the official message. The suggestions are the most likely causes: the application's log or Event Viewer remains the reference.
To go further: Windows 11 maintenance and repair details DISM, SFC and the recovery environment, and the "My PC won't start" assistant guides the diagnosis of blue screens at startup.