The api.def already has the winapi functions defined for reading/writing ini files.
GetPrivateProfileInt;kernel32!GetPrivateProfileIntA
GetPrivateProfileString;kernel32!GetPrivateProfileStringA
WritePrivateProfileString;kernel32!WritePrivateProfileStringA
GetPrivateProfileSection;kernel32!GetPrivateProfileSectionA
WritePrivateProfileSection;kernel32!WritePrivateProfileSectionA