The bootloader "disappeared" because you re-installed Windows. Windows would always write at the Master Boot Record to make the system boot to Windows directly. It overwrites the MBR data of the bootloader, thus, the bootloader would not boot anymore.
The solution is to re-install the bootloader. However, I am not familiar with SUSE because I only use Ubuntu. But there maybe some similarities though.
This is for installing GRUB:
You could use an Ubuntu Live CD, then boot from it. After booting from it, open up the terminal and run "sudo grub-install /dev/sda6". The /dev/sda6 is arbitrary. I don't know how to do it from SUSE but I have a hunch that SUSE also comes with a "rescue mode" like Ubuntu does. Anyway, you could install the bootloader from any OS even in Windows. Just install the Windows-version of GRUB. I do not know anything about LILO so I am just elaborating more on GRUB.
you have to reinstall bootloader, i think that SUSE have like Mandriva ˇsystem rescueˇ on their install dvds or cds