SHDeleteValueW

// SHLWAPI.dll  (Unicode / -W)
#include <windows.h>

WIN32_ERROR SHDeleteValueW(
    HKEY hkey,
    LPCWSTR pszSubKey,   // optional
    LPCWSTR pszValue
);

<DllImport("SHLWAPI.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function SHDeleteValueW(
    hkey As IntPtr,   ' HKEY
    <MarshalAs(UnmanagedType.LPWStr)> pszSubKey As String,   ' LPCWSTR optional
    <MarshalAs(UnmanagedType.LPWStr)> pszValue As String   ' LPCWSTR
) As UInteger
End Function

' hkey : HKEY
' pszSubKey : LPCWSTR optional
' pszValue : LPCWSTR
Declare PtrSafe Function SHDeleteValueW Lib "shlwapi" ( _
    ByVal hkey As LongPtr, _
    ByVal pszSubKey As LongPtr, _
    ByVal pszValue As LongPtr) As Long
' Unicode(W): 文字列は ByVal As LongPtr とし StrPtr(unicodeStr) を渡す
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

SHDeleteValueW = ctypes.windll.shlwapi.SHDeleteValueW
SHDeleteValueW.restype = wintypes.DWORD
SHDeleteValueW.argtypes = [
    wintypes.HANDLE,  # hkey : HKEY
    wintypes.LPCWSTR,  # pszSubKey : LPCWSTR optional
    wintypes.LPCWSTR,  # pszValue : LPCWSTR
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHLWAPI.dll')
SHDeleteValueW = Fiddle::Function.new(
  lib['SHDeleteValueW'],
  [
    Fiddle::TYPE_VOIDP,  # hkey : HKEY
    Fiddle::TYPE_VOIDP,  # pszSubKey : LPCWSTR optional
    Fiddle::TYPE_VOIDP,  # pszValue : LPCWSTR
  ],
  -Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "shlwapi")]
extern "system" {
    fn SHDeleteValueW(
        hkey: *mut core::ffi::c_void,  // HKEY
        pszSubKey: *const u16,  // LPCWSTR optional
        pszValue: *const u16  // LPCWSTR
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SHLWAPI.dll", CharSet = CharSet.Unicode)]
public static extern uint SHDeleteValueW(IntPtr hkey, [MarshalAs(UnmanagedType.LPWStr)] string pszSubKey, [MarshalAs(UnmanagedType.LPWStr)] string pszValue);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHLWAPI_SHDeleteValueW' -Namespace Win32 -PassThru
# $api::SHDeleteValueW(hkey, pszSubKey, pszValue)

#uselib "SHLWAPI.dll"
#func global SHDeleteValueW "SHDeleteValueW" wptr, wptr, wptr
; SHDeleteValueW hkey, pszSubKey, pszValue   ; 戻り値は stat
; hkey : HKEY -> "wptr"
; pszSubKey : LPCWSTR optional -> "wptr"
; pszValue : LPCWSTR -> "wptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "SHLWAPI.dll"
#cfunc global SHDeleteValueW "SHDeleteValueW" sptr, wstr, wstr
; res = SHDeleteValueW(hkey, pszSubKey, pszValue)
; hkey : HKEY -> "sptr"
; pszSubKey : LPCWSTR optional -> "wstr"
; pszValue : LPCWSTR -> "wstr"

; WIN32_ERROR SHDeleteValueW(HKEY hkey, LPCWSTR pszSubKey, LPCWSTR pszValue)
#uselib "SHLWAPI.dll"
#cfunc global SHDeleteValueW "SHDeleteValueW" intptr, wstr, wstr
; res = SHDeleteValueW(hkey, pszSubKey, pszValue)
; hkey : HKEY -> "intptr"
; pszSubKey : LPCWSTR optional -> "wstr"
; pszValue : LPCWSTR -> "wstr"

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	shlwapi = windows.NewLazySystemDLL("SHLWAPI.dll")
	procSHDeleteValueW = shlwapi.NewProc("SHDeleteValueW")
)

// hkey (HKEY), pszSubKey (LPCWSTR optional), pszValue (LPCWSTR)
r1, _, err := procSHDeleteValueW.Call(
	uintptr(hkey),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pszSubKey))),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pszValue))),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // WIN32_ERROR

function SHDeleteValueW(
  hkey: THandle;   // HKEY
  pszSubKey: PWideChar;   // LPCWSTR optional
  pszValue: PWideChar   // LPCWSTR
): DWORD; stdcall;
  external 'SHLWAPI.dll' name 'SHDeleteValueW';

result := DllCall("SHLWAPI\SHDeleteValueW"
    , "Ptr", hkey   ; HKEY
    , "WStr", pszSubKey   ; LPCWSTR optional
    , "WStr", pszValue   ; LPCWSTR
    , "UInt")   ; return: WIN32_ERROR

●SHDeleteValueW(hkey, pszSubKey, pszValue) = DLL("SHLWAPI.dll", "dword SHDeleteValueW(void*, char*, char*)")
# 呼び出し: SHDeleteValueW(hkey, pszSubKey, pszValue)
# hkey : HKEY -> "void*"
# pszSubKey : LPCWSTR optional -> "char*"
# pszValue : LPCWSTR -> "char*"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。
# ※-W(Unicode)関数。なでしこ1はANSIのため -A 版の利用を推奨。