1) Open Regional and Language Options window by pressing Windows + R and type intl.cpl .
3) Go to “Time” tab and you’ll see the value of “Long time” will be set to HH:mm:ss. Just add tt at last of the value, i.e. change the value to HH:mm:ss tt
4) If you want to show the time in 12 hour format (06:30 instead of 18:30), then change the value to hh:mm:ss tt