I can't do an actualization to my Phone to the 18.3.1.C.0.21 version

[bellayn]

It download the versión but it doesn't upgrade what can I do?

[Uliwooly]

Uninstall > restart your PC > install PCC > restart your PC > try again 

PC Companion (PCC)

Bridge (for Mac)

Alternatives on How to backup Xperias

http://talk.sonymobile.com/thread/36355

[Uliwooly]

Just to make sure, on your phone 

settings > about phone > which version do you currently have? 

Settings > about phone > software update > do you get a notification?