Missing selection boot (Ubuntu and Windows XP Pro)

Hi,
I have windows XP Pro and Ubuntu 8.04 which working perfectly.
Currently i just finished updating from Ubuntu 8.04 to Ubuntu 8.10 without any error but i just found out that my dual boot is missing.

How do I enable them back as before?

Here is my fdisk information:

Disk /dev/sda: 41.1 GB, 41110142976 bytes
255 heads, 63 sectors/track, 4998 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xc983c983

   Device Boot Start End Blocks Id System
/dev/sda1 * 1 4997 40138371 7 HPFS/NTFS

Disk /dev/sdb: 60.0 GB, 60022480896 bytes
255 heads, 63 sectors/track, 7297 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000001

   Device Boot Start End Blocks Id System
/dev/sdb1 1 7296 58605088+ 7 HPFS/NTFS