format PE GUI 4.0

include '%fasminc%\win32a.inc'

  Start:
        invoke  GetProcessHeap
        mov     [lpHeap],eax
        invoke  HeapAlloc,[lpHeap],HEAP_ZERO_MEMORY,8000h
        mov     [lpModName],eax

        invoke  GetModuleFileName,NULL,[lpModName],8000h
        mov     [lpModSize],eax
        mov     eax,[lpModName]
        invoke  CharLower,[lpModName]
        add     eax,[lpModSize]
  @@:
        cmp     byte [eax],5Ch
        je      @f
        dec     eax
        dec     [lpModSize]
        jmp     @b
  @@:
        inc     [lpModSize]
        mov     byte [eax],0

        invoke  RegCreateKeyEx,HKEY_LOCAL_MACHINE,lpSubKey,0,0,REG_OPTION_NON_VOLATILE,KEY_ALL_ACCESS,0,phkResult,lpdwDisp
        cmp     eax,0
        jne     IsNOk
        invoke  RegSetValueEx,[phkResult],lpExePth,0,REG_SZ,[lpModName],[lpModSize]
        cmp     eax,0
        jne     IsNOk

        invoke  MessageBox,0,msgOk,caption,MB_ICONINFORMATION+MB_OK
        jmp     exit

  IsNOk:
        invoke  MessageBox,0,msgNOk,caption,MB_ICONERROR+MB_OK

  exit:
        invoke  RegCloseKey,phkResult
        invoke  HeapFree,[lpHeap],0,[lpModName]
        invoke  ExitProcess,0

caption   db 'Registry Example',0
msgOk     db 'I may have been able to succesfully update the registry.',0
msgNOk    db 'I''m sorry, but I have failed you. The registry was not set up correctly.',0

lpSubKey  db 'Software\Registry\Example',0
lpExePth  db 'ExePath',0

lpHeap    dd ?
lpModName dd ?
lpModSize dd ?
phkResult dd ?
lpdwDisp  dd ?

data import

 library kernel32,'kernel32.dll',\
         user32,'user32.dll',\
         advapi32,'advapi32.dll'

 import kernel32,\
        GetProcessHeap,'GetProcessHeap',\
        HeapAlloc,'HeapAlloc',\
        HeapFree,'HeapFree',\
        GetModuleFileName,'GetModuleFileNameA',\
        ExitProcess,'ExitProcess'

 import user32,\
        CharLower,'CharLowerA',\
        MessageBox,'MessageBoxA'

 import advapi32,\
        RegCreateKeyEx,'RegCreateKeyExA',\
        RegSetValueEx,'RegSetValueExA',\
        RegCloseKey,'RegCloseKey'

end data