windows detect system dark mode

To detect the system dark mode in Windows using Assembly language, you can use the Windows API function RegGetValueA to retrieve the value of the AppsUseLightTheme registry key. Here's an example code snippet that demonstrates how to do this:

section .data
    regKey db "SOFTWARE\Microsoft\Windows\CurrentVersion\Themes\Personalize",0
    regValue db "AppsUseLightTheme",0
    regType dd 4 ; REG_DWORD
    regData dd 0
    regDataSize dd 4

section .text
    extern RegGetValueA : proc

    global _start
        ; Open the registry key
        push 0 ; hKey = HKEY_CURRENT_USER
        push offset regKey
        push 0 ; Reserved = NULL
        push 0x20019 ; KEY_QUERY_VALUE | KEY_WOW64_64KEY
        call RegOpenKeyExA
        add esp, 16

        ; Read the registry value
        push eax ; hKey
        push offset regValue
        push 0 ; Reserved = NULL
        push offset regType
        push offset regData
        push offset regDataSize
        call RegGetValueA
        add esp, 24

        ; Check the value of the registry key
        cmp dword [regData], 0
        je light_theme
        ; Dark theme code here
        jmp exit

        ; Light theme code here

        ; Close the registry key
        push eax ; hKey
        call RegCloseKey
        add esp, 4

        ; Exit the program
        push 0
        call ExitProcess

Please note that this code snippet is just an example and may need to be modified to fit your specific requirements. It assumes that you are familiar with Assembly language programming and the Windows API.