Computer display problems on my projector, can you please help?

So I've been using my projector as a monitor for my pc for about a year and a half and my computer got a bug on the disk drive, I got my pc fixed and brought it home but for some reason my projector displays the first loading bar thing then it blanks and says no signal but my dads monitor works for the pc and the projector works for my xbox 360 using the same HDMI cable what do you think I can do to make my projector work with my computer?