if you want to make this code more efficient, you can go for something like
```
private static final boolean IS_WINDOWS =  System.getProperty("os.name").startsWith("Windows");

public static final boolean isWindows() {
    return IS_WINDOWS;
}
```

That way the check happens only once at class loading and initialization time. Since we do not assume that we change the OS underneath a running JVM, it should be fine ;-)