|The hard drive is not supposed to repeatedly click (some click once) - assuming your AC adapter and/or main battery is fine, that usually means the hard drive is dying or dead.|
If you normally see the model number of your hard drive while booting, probably on the first black screen if that isn't obscured by a logo screen (Acer graphic), check to see whether you are still seeing it. If you aren't, and you normally do, the hard drive is dead. If you do, and you normally do, the hard drive may be dying.
If you know how to get into your bios Setup, go there and see if there is somewhere where you can detect the hard drive (and sometimes the CD drive)on your computer and display it (them) in a list. If you have that and the hard drive is not detected, it is dead.
check your hard drive.
See the latter part of response 1 in this:
If you don't have a floppy drive, you can get a CD image diagnostic utility from most web sites, but obviously you would need to make a burned CD, preferably a CD-R for best compatibilty, on another computer.
If the utility does not find the hard drive, and you haven't been fiddling with the hard drive physically, it is dead.