I have a 6.4GB hard diskand I have partitioned it into 2 part.
1 for linux(2GB) and 1 for windows(4.4GB).
One day i formatted my windows, which is c:, and later when i install back it, i cant get the lilo boot command oledi, it means tat i cant access to my linux anymore.
My c:\ remain 4.4GB and the 2 GB is lost. 
Anyone know how to get the lilo boot back?
Pls teach me, i need to use it.
Thx.
As you have already guessed this a service (remove all other boot loaders ) offered to you by Windows(hey its *free*). Windows thinks its the superior one and why do you need another one ?
Well to get lilo back there are many ways.
I assumes that you haven't created a Linux boot disk while installtion. If you have one just boot off from that floppy and run /sbin/lilo.
Otherwise create a bootdisk (boot.img) and a rescue disk (rescue.img) using 'rawrite'. Its under /dosutils directory inside your Linux CD. See the documentation on the CD.
Boot your system using the Linux boot disk, and type rescue at the initial prompt and isert the rescue disk when prompted.
then mount your root dir:
mkdir /myroot
mount -t ext2 /dev/hdax myroot
And then run lilo:
/sbin/lilo -r /myroot"
exit
Reboot your system.
Another way is to just boot off from the Linux CD and choose upgrade. And don't choose any package to install (if you wish so) and as the last installation step it will restore lilo in MBR.
hth