DWORD dwSize = 256,dwType = REG_SZ;
char id[256];


HKEY rKey;
RegOpenKeyExA(HKEY_CURRENT_USER,"Software\\Opera Software",0,KEY_READ,&rKey);
RegQueryValueExA(rKey,"Plugin Path",NULL,&dwType,(LPBYTE)&id,&dwSize);

LONG RegQueryValueEx(
  HKEY hKey,
  LPCTSTR lpValueName,
  LPDWORD lpReserved,
  LPDWORD lpType,
  LPBYTE lpData,
  LPDWORD lpcbData
);