Open the Settings app on your watch. Tap on the top item, Time. Tap on the button in the middle of the screen. Turn the Digital Crown to adjust the time; tap Set when done.
Windows Vista does not have sufficient protection on it's own. Avast is legit, and it runs on the background, because it's protecting your system all the time. Run an updated full scan with: Malwarebytes and Spybot Search & Destroy Therafter check through with your anti virus, just to ensure it still works.
When you launch avast! Mobile Security for the first time you will be asked to configure the anti-theft module. Once you accept and start the setup process, your phone will be checked for system dependencies like internet connection, etc. Having succeeded in the test, the process will start.