According to the official specs, the available Android version for this phone is Android OS, v2.3 (Gingerbread). If you have 2.2.1, you can upgrade it using Kies, the official Samsung application or through the OTA (Over The Air). Download Kies and install it, then connect the phone and make sure it's charged up to 85 %. The software will prompt you to upgrade the firmware of your device. Proceed with the installation, and at the end of it you will have Android 2.2.3. This is the latest version supported by the phone.