Apple has just released iOS 4.3.1 for the iPhone 4, iPhone 3GS, iPad, iPad2, iPod Touch 3G and iPod Touch 4G. The update features nothing new just a few performance enhancements, bug fixes, vulnerabilities and backup improvements.
Just like all the previous updates to install iOS 4.3.1 all you have to do is connect your iDevice using a USB cable to your PC and open iTunes. A prompt shall open and ask you to install the latest update, accept and in a few minutes your device would be running on iOS 4.3.1
You can grab the update for your iDevice using the following links:
To get iTunes 10.2.1 click Download