the hard reset the phone will reinstall the software included.
Note: Backup the files that you want to keep, before you perform a hard reset. You can backup files via a computer or a memory card.
firmware update with PC companion softwareDownload PC companion and install
Install PC companion on your PC computer. Follow instruction. For firmware update you need a micro USB cable. When the pc recognizing your XPERIA Ray it will install the necessary driver files.
After your XPERIA Ray connected press Start / in Support Zone
You can also use Sony Ericsson update service tool
PC Suite is out of date use PC companion software instead
If nothing works: As last resort do a Sony Ericsson phone repaire with PC Suite. Use this method to hard reset AFTER INSTALLATION----> TOOLS > PHONE REPAIR