HKLM64 vs HKLM?

[VAN0]

Hello.

The help file is not clear on what HKLM64 exactly does.

1) Does it effect script compiled as 64bit or 32bit, or does it only affect on what OS it's being executed on?

2) if using 32bit script I want to write into HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\my_key on 64bit OS and HKEY_LOCAL_MACHINE\SOFTWARE\my_key on 32bit OS, what path do I use in my script? So far in my tests it doesn't matter what I use HKLM or HKLM64, it always writes into HKEY_LOCAL_MACHINE\SOFTWARE\my_key which suggests that we have to run a check what type of script is running and then use appropriate paths for each versions separately...making HKLM64 useless when compiling both 32 and 64bit

Thank you.

[careca]

Wow6432Node Registry Key

The Wow6432Node registry entry indicates that you are running a 64-bit Windows version.

The operating system uses this key to display a separate view of HKEY_LOCAL_MACHINE\SOFTWARE for 32-bit applications that run on 64-bit Windows versions. When a 32-bit application writes or reads a value under the HKEY_LOCAL_MACHINE\SOFTWARE\<company>\<product> subkey, the application reads from the HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\<company>\<product> subkey.

A registry reflector copies certain values between the 32-bit and 64-bit registry views (mainly for COM registration) and resolves any conflicts using a "last-writer-wins" approach.

https://www.advancedinstaller.com/user-guide/registry-wow6432-node.html

[VAN0]

This does not explain why when I run script on 64bit machine (via F5 in SciTe4), it always writes as HKEY_LOCAL_MACHINE\SOFTWARE\my_key regardless if I use HKLM or HKLM64

Edited November 24, 2018 by VAN0

[Subz]

When you setup AutoIt on your system did you use "Use native x64 tools by default" or "Use x86 tools by default (recommended for compatibility).  Because if you used the recommended method RegWrite will write to HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\my_key.  You can test by running the following via F5:

#RequireAdmin
#Region ;**** Directives created by AutoIt3Wrapper_GUI ****
#AutoIt3Wrapper_UseX64=n
#EndRegion ;**** Directives created by AutoIt3Wrapper_GUI ****
RegWrite("HKEY_LOCAL_MACHINE\SOFTWARE\my_key", "Value", "REG_SZ", "Data")

Also HKLM and HKLM64 are really only for 32-bit scripts, on a 64-bit machine both of these will point to HKLM\SOFTWARE, in a 64-bit compiled script you would have to use HKLM or HKLM64 ...\SOFTWARE\WOW6432Node to access 32-bit node.

Edited November 24, 2018 by Subz

[VAN0]

I didn't change anything during installation of AutoIt, so it was "Use x86 tools by default"

[Subz]

So what happens when you run the script above, using F5?

[VAN0]

Your code worked fine, it created new key in HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\my_key

So, it turned out in my case it was due to fact that I was compiling both 32 and 64bit versions and had this:
 

#AutoIt3Wrapper_Compile_Both=y
#AutoIt3Wrapper_UseX64=y

Evidently this defaults to run script in 64bit?

So, back to the problem.

It seems that If one is planning on compiling script into both 32 and 64bit executable they would have to not only check what OS it's running on but also what type of executable, and then "manually" correct registry path accordingly, because we can't rely on HKLM/HKLM64

It just doesn't make sense why HKLM/HKLM64 only affects 32bit executables.

[Subz]

The only way to access 64-bit node in a 32-bit compiled script is using HKLM64 you can't access it any other way that I know of.  I have found that I can do everything I need using 32-bit compiled script and have never found a need for 64-bit.  However if you need to have both than you will need to add some instructions to the top of your script something like:

Global $sHKLM32 = @AutoItX64 = 1 ? "HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432NODE" : "HKLM\SOFTWARE"
Global $sHKLM64 = @AutoItX64 = 1 ? "HKEY_LOCAL_MACHINE\SOFTWARE" : "HKLM64\SOFTWARE"

 

Edited November 24, 2018 by Subz

[VAN0]

Thank you. I hope this will be fixed in the core, or at least added into the documentation.

P.S.

Not to be nit-picky, but I think you meant this:

Global $sHKLM32 = @AutoItX64 = 1 ? "HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432NODE" : "HKLM\SOFTWARE"
Global $sHKLM64 = @AutoItX64 = 1 ? "HKEY_LOCAL_MACHINE\SOFTWARE" : "HKLM64\SOFTWARE"

 

[Subz]

 Actually was just in the process of changing the code, but glad you picked it up.

[Nine]

you can also add one line if you are reading keys from the OS automatically. For example :

Global $sHKLM32 = @AutoItX64 = 1 ? "HKLM\SOFTWARE\WOW6432NODE" : "HKLM\SOFTWARE"
Global $sHKLM64 = @AutoItX64 = 1 ? "HKLM\SOFTWARE" : "HKLM64\SOFTWARE"

Global $sHKLM = @OSarch = "X64" ? $sHKLM64 : $sHKLM32

Global $vResult = RegRead($sHKLM & "\Microsoft\Windows NT\CurrentVersion\Winlogon","AutoAdminLogon")
    If @error Then MsgBox(4096, "Error", "Error reading registry key: " & @error)
Switch $vResult
    Case 1
        MsgBox(4096, "Result", "Autologon Enabled / " & @extended)
    Case Else
        MsgBox(4096, "Result", "Autologon Disabled / " & @extended)
EndSwitch