Need Help Powering on Computer properly

[808Boy]

Recently my eMachines microsoft xp, has had problems powering on.
If I try to turn on my computer the fan would go crazy but the monitor would stay in its "idle" state.
So I am forced to manually turn off the computer by holding down the power button. However the second time I try to power on the computer the fan goes on briefly and then the computer would operate normally.
This is how I have been powering my computer on. (Power it on, it wont work so manually turn it off, turn it on) It always works on the second try.
Even when I try to restart the computer the monitor would power off as usual but it would never turn on again and it would stay in its idle state again. Thus causing me to use the manual power option.
Not to long ago i observed my dad play poker and he had clicked on a pop up which stopped him from continueing as it froze the web browser. I told him to turn it off and he went straight into the manual power button without trying to power it off properly. I dont know if this is related or how long he has been doing this.
Yes I have tried restoring the OS but the problem still persists, thanks for any help you can give me

 

[AlbertLionheart]

There was a thread about this some weeks ago relating to emachine PSUs and their reliability. Also I remember some reference to PSUs doing more damage when they finally give up - like trashing main boards.
Suggest you try a replacement PSU before doing anything else but it might be worth trying to trace the earlier thread.