What is the difference between Win32, HRESULT and NTSTATUS codes?

Win32 error codes are small positive integers returned by GetLastError, such as 5 for access denied. HRESULT codes are 32-bit values used by COM and modern APIs, typically shown in hex like 0x80070005, where the low 16 bits often wrap a Win32 code. NTSTATUS values come from the kernel and driver layer, usually starting 0xC0000000 for errors.

Why is 0x80070005 the same as error 5?

0x80070005 is an HRESULT that wraps the Win32 error 5 (ERROR_ACCESS_DENIED). The 0x8007 prefix means 'this HRESULT carries a Win32 facility code', and the low word 0x0005 is the original Win32 number. That is why both mean access denied.

How do I see the error behind a failed operation?

In code, call GetLastError immediately after a failing Win32 call, or read the HRESULT returned by a COM method. On the command line, 'net helpmsg ' translates a Win32 error, and many tools print the hex HRESULT directly. Then look the value up here.

Are these every Windows error code?

No. Windows defines thousands of codes across many components. This tool covers the most commonly encountered Win32, HRESULT and NTSTATUS values. For rare or component-specific codes, consult Microsoft's system error code documentation.

Is my input sent anywhere?

No. The code list ships with the page and every lookup happens in your browser.

Windows Error Codes — Gera Tools

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Decode a Windows error code in seconds

Windows surfaces failures as numbers — a Win32 error like 5, an HRESULT like 0x80070005, or an NTSTATUS like 0xC0000022. They look cryptic but each maps to a symbolic name and a concrete meaning. This tool takes a decimal or hexadecimal value (or a name) and tells you the layer it came from, what it means, and the first thing to check.

How it works

The page carries a curated list of common error codes, each tagged with its layer (Win32, HRESULT, or NTSTATUS), its symbolic name, meaning, and a fix hint. Your input is normalised: a leading 0x marks a hexadecimal value, which is parsed and matched against entries stored as hex; a bare integer is matched as a Win32 decimal code. HRESULTs that carry a Win32 facility (the 0x8007xxxx form) are cross-referenced so that 0x80070005 and 5 both resolve to access-denied. Text queries match the symbolic name and meaning.

Tips and notes

When you only have a Win32 number, net helpmsg 5 prints the text on any Windows machine. For HRESULTs, remember the 0x8007 prefix means a wrapped Win32 code — strip it to the low word and you often get a familiar error. NTSTATUS values (usually 0xC0000000+) come from drivers and the kernel; they are translated to Win32 errors by RtlNtStatusToDosError before most apps see them. Always capture the error immediately after the failing call, because a later API call will overwrite the thread’s last-error value. This list covers the common cases; the full Microsoft system-error documentation is authoritative for the rest.