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

[munya]

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..