Its simple
Start -> Control Pannel -> Regional and LAnguage option -> Customize (beside English US) -> Go to TIME tab -> Change AM symbol and PM symbol from AM and PM to ur name -> Apply -> Ok …
IS it changed ??? Might be not …
Now go to time in taskbar and Double Click it to open “Date and time property” …
Look place where time chnges in digital form i.e. 02:47:52 AM , click to arrow to cnage the AM or PM by selecting and press arrow. It will Show ur name or name that was entered by u, Apply -> OK and be HAPPY 🙂