private void checkKeyExists(
                             String rootKey,
                             String keyPath,
                             String keyName ) {

    try {
        WinReg.HKEY rootHKey = getHKey(rootKey);
        if (!Advapi32Util.registryValueExists(rootHKey, keyPath, keyName)) {
            throw new RegistryOperationsException("Registry key does not exist. "
                                                  + getDescription(rootKey, keyPath, keyName));
        }
    } catch (Win32Exception e) {
        throw new RegistryOperationsException("Registry key path does not exist. "
                                              + getDescription(rootKey, keyPath, keyName), e);
    }
}
 

/**
 * Returns the osu! installation directory.
 * @return the directory, or null if not found
 */
private static File getOsuInstallationDirectory() {
	if (!System.getProperty("os.name").startsWith("Win"))
		return null;  // only works on Windows

	// registry location
	final WinReg.HKEY rootKey = WinReg.HKEY_CLASSES_ROOT;
	final String regKey = "osu\\DefaultIcon";
	final String regValue = null; // default value
	final String regPathPattern = "\"(.+)\\\\[^\\/]+\\.exe\"";

	String value;
	try {
		value = Advapi32Util.registryGetStringValue(rootKey, regKey, regValue);
	} catch (Win32Exception e) {
		return null;  // key/value not found
	}
	Pattern pattern = Pattern.compile(regPathPattern);
	Matcher m = pattern.matcher(value);
	if (!m.find())
		return null;
	File dir = new File(m.group(1));
	return (dir.isDirectory()) ? dir : null;
}
 

public static boolean isAddedToContextMenu() {
    if (!Platform.isWindows()) {
        return false;
    }
    final WinReg.HKEY REG_CLASSES_HKEY = WinReg.HKEY_LOCAL_MACHINE;
    final String REG_CLASSES_PATH = "Software\\Classes\\";
    try {
        if (!Advapi32Util.registryKeyExists(REG_CLASSES_HKEY, REG_CLASSES_PATH + ".swf")) {
            return false;
        }
        String clsName = Advapi32Util.registryGetStringValue(REG_CLASSES_HKEY, REG_CLASSES_PATH + ".swf", "");
        if (clsName == null) {
            return false;
        }
        return Advapi32Util.registryKeyExists(REG_CLASSES_HKEY, REG_CLASSES_PATH + clsName + "\\shell\\ffdec");
    } catch (Win32Exception ex) {
        return false;
    }
}
 

String getToken(
    final Sspi.CtxtHandle continueCtx,
    final Sspi.SecBufferDesc continueToken,
    final String targetName) {
    final IntByReference attr = new IntByReference();
    final ManagedSecBufferDesc token = new ManagedSecBufferDesc(
        Sspi.SECBUFFER_TOKEN, Sspi.MAX_TOKEN_SIZE);

    sspiContext = new Sspi.CtxtHandle();
    final int rc = Secur32.INSTANCE.InitializeSecurityContext(clientCred,
        continueCtx, targetName, Sspi.ISC_REQ_DELEGATE | Sspi.ISC_REQ_MUTUAL_AUTH, 0,
        Sspi.SECURITY_NATIVE_DREP, continueToken, 0, sspiContext, token,
        attr, null);
    switch(rc) {
        case WinError.SEC_I_CONTINUE_NEEDED:
            continueNeeded = true;
            break;
        case WinError.SEC_E_OK:
            dispose(); // Don't keep the context
            continueNeeded = false;
            break;
        default:
            dispose();
            throw new Win32Exception(rc);
    }
    return Base64.encodeBase64String(token.getBuffer(0).getBytes());
}
 

private File loadOsuInstallationDirectory() {
	if (!System.getProperty("os.name").startsWith("Win")) {
		return null;
	}

	final WinReg.HKEY rootKey = WinReg.HKEY_CLASSES_ROOT;
	final String regKey = "osu\\DefaultIcon";
	final String regValue = null; // default value
	final String regPathPattern = "\"(.+)\\\\[^\\/]+\\.exe\"";

	String value;
	try {
		value = Advapi32Util.registryGetStringValue(rootKey, regKey, regValue);
	} catch (Win32Exception ignored) {
		return null;
	}
	Pattern pattern = Pattern.compile(regPathPattern);
	Matcher m = pattern.matcher(value);
	if (!m.find()) {
		return null;
	}
	File dir = new File(m.group(1));
	if (dir.isDirectory()) {
		return dir;
	}
	return null;
}
 

@Override
public MemoryBuffer read(Pointer address, int size, MemoryBuffer buffer) {
    if (Kernel32.ReadProcessMemory(pointer(), address, buffer, size, 0) == 0) {
        throw new Win32Exception(Native.getLastError());
    }
    return buffer;
}
 

@Override
public Process write(Pointer address, MemoryBuffer buffer) {
    if (Kernel32.WriteProcessMemory(pointer(), address, buffer, buffer.size(), 0) == 0) {
        throw new Win32Exception(Native.getLastError());
    }
    return this;
}
 

@Override
public MemoryBuffer read(Pointer address, int size, MemoryBuffer buffer) {
    if (Kernel32.ReadProcessMemory(pointer(), address, buffer, size, 0) == 0) {
        throw new Win32Exception(Native.getLastError());
    }
    return buffer;
}
 

@Override
public Process write(Pointer address, MemoryBuffer buffer) {
    if (Kernel32.WriteProcessMemory(pointer(), address, buffer, buffer.size(), 0) == 0) {
        throw new Win32Exception(Native.getLastError());
    }
    return this;
}
 

@Nullable
public static String readString(WinReg.HKEY hkey, String key, String valueName) {
    if (! isAvailable()) {
        return null;
    }
    try {
        return Advapi32Util.registryGetStringValue(hkey, key, valueName);
    } catch (Win32Exception e) {
        return null;
    }
}
 

/**
 * Gets the computer name.
 * 
 * <p>This is the also known as the NetBIOS name, although NetBIOS is 
 * hardly used anymore. It is the same value as can be seen from the
 * {@code COMPUTERNAME} environment variable.
 * 
 * <p>
 * Windows API equivalent: {@code GetComputerName()} function from 
 * {@code Kernel32} library.
 * 
 * @return computer name
 * @throws NativeException if there was an error executing the
 *    system call.
 */
public static String getComputerName() throws NativeException {
    try {
        return Kernel32Util.getComputerName();
    } catch (Win32Exception ex) {
        LOGGER.log(Level.FINE, "Kernel32.GetComputerName error : {0}", ex.getHR().intValue());
        String env = System.getenv("COMPUTERNAME");
        if (env != null) {
            return env;
        }
        throw new NativeException(ex.getHR().intValue(), "error calling 'GetComputerName()' function");
    }
}