i made this code, but did not work. I want to put some data to registry, more exactly a path. Tho code make a key, but did not set the value. Please help

HKEY hkey;
DWORD dwDisposition;
unsigned char boum[7] = "chaine";
int dwSize = sizeof (DWORD);


RegCreateKeyEx(HKEY_LOCAL_MACHINE, TEXT("Software\\My Company\\My Application"), 0, NULL, 0, 0, NULL, &hkey, &dwDisposition);
RegSetValueExA(hkey, "La Chaine", NULL, REG_SZ, (LPBYTE)&boum, dwSize);