Cant get my computor to run programs

Hello All,
I am asking for help with this 1 year old desktop Acer M5640 . All this unit does now is lets me power up the unit with the blue light lit but thats it oo yes the fan runs also an if i need to put a disk in it will open up the disk player but it doesnt run it. It also says no signal on the monitor. Thats it.. It doesnt run any programs like it did before when i would hit the power on button i could see the flickering of light on the bottom which was booting up the system now its just does nothing. I would greatly appreciate any help in this matter.once again i would like to thank everyone here for a helping hand in this matter.. Thank you all

Hello i hit the power button on an the blue light comes on showing power an the fan runs but it doesnt run any start up programs that i wwould see a blue light flickering on the bottom of the hard drive unit the M5640. It doesnt do any thing any more and the signal it says no signal on the screen. The screen its on now is a CRT old screen but i have a new 22" LCD screen and it does the same. I just dont know what is happening with this unit.its only a little over a year old.

Hello yes the hard drive light comes on .. The power button when i hit it on lights up an stays on. Before when i would hit the power button on it would stay blue an there is a buttom light that would flicker when it was booting up the start up programs. that doesnt do that any more. All it does is keep the power button ligth on. the fan runs an if i put a disk in the disk player it will open it up but not play it. The monitor says there is no signal also.