AutoHotkey Community

hKey = HKEY_LOCAL_MACHINE
sKeyName = SYSTEM
sValueName = InstallLocation
KEY_QUERY_VALUE = 0x1

DllCall("Advapi32.dll\RegOpenKeyEx", Str,hKey, Str,sKeyName, Int,0, Int,KEY_QUERY_VALUE, "UInt *",tmpHandle)
DllCall("Advapi32.dll\RegQueryValue", "UInt *",tmpHandle, Str,sValueName, Str,vValue)

MsgBox, %vValue%

DllCall("Advapi32.dll\RegOpenKeyEx", Str,hKey, Str,sKeyName, Int,0, Int,KEY_QUERY_VALUE, "UInt *",tmpHandle)
MsgBox, % Errorlevel ; if -4 ,  try calling RegOpenKeyExA

hKey = HKEY_LOCAL_MACHINE
sKeyName = SYSTEM
sValueName = InstallLocation
KEY_QUERY_VALUE = 0x1

DllCall("Advapi32.dll\RegOpenKeyExA", Str,hKey, Str,sKeyName, Int,0, Int,KEY_QUERY_VALUE, "UInt *",tmpHandle)
MsgBox, % Errorlevel ; This is  now returning 0

DllCall("Advapi32.dll\RegQueryValueExA", "UInt *",tmpHandle, Str,sValueName, Int,0, Int,0, Str,vValue)
MsgBox, % Errorlevel ; This is returning A-4
MsgBox, %vValue%

DllCall("Advapi32.dll\RegOpenKeyExA", Str,hKey, Str,sKeyName, Int,0, Int,KEY_QUERY_VALUE, "UInt *",tmpHandle)
MsgBox, % tmpHandle ; What shows up ?

; fourth parameter not required while retrieving default value
MsgBox, % RegRead( Data, "HKLM", "SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\IEXPLORE.exe"  )
MsgBox, % Data

; Retrieving Text
MsgBox, % RegRead( Data, "HKLM", "SOFTWARE\AutoHotkey", "InstallDir" )
MsgBox, % Data

;HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation

; Retrieving DWord
MsgBox, % RegRead( Data, "HKLM", "SYSTEM\CurrentControlSet\Control\TimeZoneInformation", "Bias" )
MsgBox, % NumGet( Data )

; Retrieving Binary
MsgBox, % RegRead( FileTime, "HKLM", "SYSTEM\CurrentControlSet\Control\Windows", "ShutdownTime" ) ; XP Only
; FILETIME Structure needs to be processed with FileTimeToSystemTime()
; www.msdn.microsoft.com/en-us/library/ms724280(VS.85).aspx
Return

RegRead( byRef Data, RootKey="", SubKey="", ValueName="" ) {
 IfEqual,RootKey,HKCR, SetEnv, RootKey, 0x80000000 ; HKEY_CLASSES_ROOT
 IfEqual,RootKey,HKCU, SetEnv, RootKey, 0x80000001 ; HKEY_CURRENT_USER
 IfEqual,RootKey,HKLM, SetEnv, RootKey, 0x80000002 ; HKEY_LOCAL_MACHINE
 IfEqual,RootKey,HKU , SetEnv, RootKey, 0x80000003 ; HKEY_USERS
 IfEqual,RootKey,HKPD, SetEnv, RootKey, 0x80000004 ; HKEY_PERFORMANCE_DATA
 IfEqual,RootKey,HKPD, SetEnv, RootKey, 0x80000005 ; HKEY_CURRENT_CONFIG
 KEY_QUERY_VALUE = 0x1
 DllCall( "Advapi32.dll\RegOpenKeyExA", UInt,RootKey, UInt,0, UInt,0, Int,0x1, UIntP,hKey)
 Loop, Parse, SubKey, \
  {
    DllCall( "Advapi32.dll\RegOpenKeyExA"
            , UInt,hKey, Str,A_LoopField, Int,0, UInt,0x1, UIntP,tmpHandle )
    DllCall( "Advapi32.dll\RegCloseKeyA", UInt,(hKey := tmpHandle) )
 }
 DllCall( "Advapi32.dll\RegQueryValueExA"
         , UInt,hKey, Str,ValueName, UInt,0, UInt,0, UIntP,Data, UIntP,RqdSz )
 VarSetCapacity( Data,RqdSz, 0 )
 DllCall( "Advapi32.dll\RegQueryValueExA"
         , UInt,hKey, Str,ValueName, UInt,0, UIntP,ValueType, Str,Data, UIntP,RqdSz )
 DllCall( "Advapi32.dll\RegCloseKeyA", UInt,hKey )
 IfEqual,ValueType,1, Return, "REG_SZ " RqdSz
 IfEqual,ValueType,2, Return, "REG_EXPAND_SZ " RqdSz
 IfEqual,ValueType,3, Return, "REG_BINARY " RqdSz
 IfEqual,ValueType,4, Return, "REG_DWORD " RqdSz
 IfEqual,ValueType,7, Return, "REG_MULTI_SZ " RqdSz
}