after i experienced this, windows 10 just updated again (after I disabled it) i had doubts if windows managed to disable this one. i tried to look at a lot of blogs and forums but so far, a lot of them suggested changing the keyboard. funny for me, i am using a laptop.
then it just hit me. i just downloaded software for screen capture and it downed on me that the software might be catching the keystrokes such as the alt+printscreen. when i closed the app, the alt+printscreen now works.
i just solved my own dilemma. hope somebody learns from this.
enjoy
coffee cup