Hi i have a problem with my coumputer

hello i have a hp and when i turned my coumputer on then it said no signeal need vga. and i putt it on and evrything was on but then coumputer dosent even work. what should i do. and my moter said sleeping, and it said no input signal i am upset.

Check your VGA cable (The Blue square one) is plugged in correctly both on your monitor and on the back of your computer. If this doesn't work your monitor may be looking for a digital input instead of the analogue one. Without knowing your monitor I can't tell you how to switch this. With the computer on you could try pressing the buttons on the monitor one at a time, one of them might switch it.