When updating, always have your seed at hand to be able to recover your funds in case of any problem.
While a crash is very unlikely, users renting or hosting might want to backup the folders “host”, “renter” and “wallet” as a security measure before the update. In Windows, they are located in the %AppData% folder (/Users/your_user/AppData/Roaming/Sia-UI/Sia). See Transferring the Client to a Different Computer for additional backup and recovery information.
Client update can be performed in several ways:
Simply use the command “siac update”
Go to “About > Check for update”