Power?

[focus_water]

when i turn on my computer it keeps restarting, it will stay on for less than a second and it would do that about 200 times.
when it restarts it makes a noise like the hard disk is starting up but it is coming from the power pack. when i press the power button that is when it will start restarting.
after it has done it about 200 times it will just stop and stay on. i press the restart button and the computer will turn on fine.

 

[Nodsu]

Maybe the PSU doesn't have enough power to start up the machine? Did you add any new hardware to your machine?

First, remove any CDs/DVDs from the drives. Then see what the thing does with the hard drive disconnected.

If it manages to start up with less load, then overloading was the cause and the solution would be a more powerful/new PSU.

 

[iss]

I would do as Nodfu suggested, if you still have the problem then replace the PSU. continued attempts to power on with a PSU that is bad could end up damaging your components.