Users who have not downloaded and installed the new Android 4.4.4 KitKat firmware update for Xperia Z1, Xperia Z1s, Xperia Z Ultra and Xperia Z1 Compact can now do it in two ways - wirelessly or via USB connection.

Using the Update Centre App

Sony Xperia Z1, Xperia Z1s, Xperia Z Ultra and Xperia Z1 Compact have the Update Centre app located in the Application menu which is used to download and install new apps and software builds from Sony Mobile.

1. Enable Wi-Fi connection or mobile data. It is recommended to use Wi-Fi due to better speed and stable connectivity than mobile data.

2. Go to the Application Menu.

3. Launch the Update Centre app.

4. Tap on the Refresh icon found at the top-right corner of the application.

5. Once a notification prompts, follow the instructions provided on the screen.

6. Downloading may take some time depending on the Internet speed and size of the firmware file.

After the download, another message will notify the user regarding the installation procedure. It will request that the battery life should be at least 50 per cent before any installation may occur. If the internal storage space is limited, the user is required to free some space.

Using Sony PC Companion or Sony Bridge

Users may also utilise a Windows computer or MAC to download and install the update via USB connection.

1. Download and install the Sony PC Companion on a Windows computer or Sony Bridge for MAC.

2. Launch the Sony PC suite installed on the machine.

3. Connect the Sony Xperia device using a USB cable and let the drivers to be installed.

4. A notification will prompt on the PC suite regarding a new firmware update.

5. Confirm the firmware download on the PC suite. Download time depends on the speed of the Internet, processing power of the computer and firmware file size.

6. After the download, proceed to installation by following the instructions provided on the screen.

Official Change Logs on Sony Xperia Z1

- Android 4.4.4 latest enhancements and security updates from Google

- Updated and improved camera experience

- Improvements to Google Voice, Contacts, Google+ and music streaming

- Latest versions of all Sony apps

- Latest bug fixes, optimisations and improvements