Win xp is not strating

Hi everyone,

I have dual boot operating system as:
C:\- Win 98 and
D:\- Win Xp Professional SP2

My computer was function normally in both the mentioned operating systems till yesterday but the problem arises when I switched off my computer during its normal shutdown process in Win XP.
Now my PC does not starts in Win XP while running successfully in Win 98.
If I want to start the PC in Win WP than it takes me to Safe-Mode screen. When I select to start the pc in safe-mode than it is going to re-boot.
If I select to start ‘Windows Normally’ than it goes to check my C:\ and after that again re-boot.
So what is the problem arises actually, I am unable to understand.
Can anyone help me??