---
name: "RegQueryInfoKeyW"
section: "3w"
platform: "linux"
package: "libwine-dev"
version: "1.4.1-4"
release: "Debian 7 (Wheezy)"
platforms: ["linux"]
url: "https://new.carta.tech/RegQueryInfoKeyW"
---

# RegQueryInfoKeyW(3w)

## NAME

**RegQueryInfoKeyW** (ADVAPI32.@)

## SYNOPSIS

LSTATUS RegQueryInfoKeyW\
  (\
   HKEY      *hkey*,\
   LPWSTR    *class*,\
   LPDWORD   *class\_len*,\
   LPDWORD   *reserved*,\
   LPDWORD   *subkeys*,\
   LPDWORD   *max\_subkey*,\
   LPDWORD   *max\_class*,\
   LPDWORD   *values*,\
   LPDWORD   *max\_value*,\
   LPDWORD   *max\_data*,\
   LPDWORD   *security*,\
   FILETIME\* *modif*\
  )

## DESCRIPTION

Retrieves information about the specified registry key.

## PARAMS

*hkey* **\[In\]**  Handle to key to query.

*class* **\[Out\]**  Buffer for *class* string.

*class\_len* **\[Out\]**  Size of *class* string buffer.

*reserved* **\[In\]**  Reserved.

*subkeys* **\[Out\]**  Buffer for number of *subkeys*.

*max\_subkey* **\[Out\]**  Buffer for longest subkey name length.

*max\_class* **\[Out\]**  Buffer for longest *class* string length.

*values* **\[Out\]**  Buffer for number of value entries.

*max\_value* **\[Out\]**  Buffer for longest value name length.

*max\_data* **\[Out\]**  Buffer for longest value data length.

*security* **\[Out\]**  Buffer for *security* descriptor length.

*modif* **\[Out\]**  Modification time.

## RETURNS

**Success:** **ERROR\_SUCCESS**

**Failure:** system error code.

## NOTES

**-** win95 allows *class* to be valid and *class\_len* to be **NULL**

**-** winnt returns **ERROR\_INVALID\_PARAMETER** if *class* is valid and *class\_len* is **NULL**

**-** both allow *class* to be **NULL** and *class\_len* to be **NULL** (it's hard to test validity, so test !NULL instead)

## IMPLEMENTATION

Declared in **"winreg.h"**.

Implemented in **"dlls/advapi32/registry.c"**.

Debug channel **"reg"**.