yes it can crash the safest ways to turn of ur comp is
1.start menu if thats unaccessible then try
2.press ctrl+alt+del then go to the option shutdown then restart or shutdown if that fails
3.Press and hold the power button or if ur comps old then press and hold the reset button.......
 
Hope that helps

yay cuse sumtimes my graphics wont work so i have to pull plug!see my forum on ati radeon sappire 9200se bluh bluh bluh

Just bear in mind that pulling the plug may cause disk corruption in the long-term

A hard shut down will not cause long term damage to disks as long as the computer is restarted fairly soon afterwards.
 
The 'damage' could be caused as a power off leaves the HDD read/write head over the disk platter and not in a neutral position as would occur if shutdown normally.
As long as you restart the HDD acts as normal and the read/write head is moved of the disk platter surface. The damage would be if the disk was'nt restarted the head would sit on the platter and possibly corrupt the surface.

my pc a emachines the green lite wont turn on.and my moniter will say no signal input.and it wont turn off by pushin the button so it i cant use it anymore.

How old is your pc and what make and windows has it got and has it got any form of pentium proccesor......
 
If you can tell me this I might be able to help you out more

sorry it wont work anymore.1 year,xp,and emachines and no amd atholon