My computer was not getting started.

Hello,

my computer was not getting started. i am using windows xp, sp2. I do not know what happened when i started my computer today it is not getting started and showing the window and stating as
we appolise for the inconvenient,but windows did

not start successfully. a recent hardware or

software change might have caused this.
If your computer stopped responding restarted

unexpectedly or was automatically shutdown to

protect your file and folder choose last known

good configuration to revert the most recent

settings that worked.
If a previous start up attempt was interrupted

due to a power failure or because the power or

reset button was pressed,or if you are not sure

what caused the problem,chosse start windows

normally.
Safemode
safemode with networking
safemode with command prompt.
last known good configuration(your most

recent settings that worked)
start windows normally.
i used every mode and it is strucking at the same window and showing same message.
I really wonder something happened to my computer. could any one help me out so that i would be thankful to you.