Samsung Xperia S system update 6.2.B.1.96 - can't install

My phone says that I have new system update available 6.2.B.1.96. I downloaded the update software but it's not installing. If I download and install the phone get restart but the software does not get installed. What could be the problem help me anyone in this process. What is proper way of upgrading sony xperia S phone ?

Thanks..

I think you are downloading on phone, but visit Sony website, directly download the update and install it as described on sonywebsite.

Is this update comes on samsung thanks to share I will also find the update.