"my acer computer won't start up" "i can hear the system running"
This is a bit complicated to understand as these two statements contradict themselves. is the PC on and working, but nothing is showing up on the screen? Or is it not?
If it IS on, but nothing on screen then you might need to readjust the video cable, make sure you have it plugged into the right port on your pc, and make sure you have the newest drivers installed.