After install ubuntu 11.04 I don't see my windows in the boot menu

Please refer to my question #168423 about boot menu. I still can not see Windows 7 and Windows XP when I boot up my PC. I went into BIOS and change the disk that I installed Ubuntu to the first boot disk. Now, I can boot directly into Ubuntu but that doesn't give me the option to select Windows. I search in the forum and see FAQ #1678 updated by delance. So, I went ahead and ran the fdisk, and below is the result:

androidba@Ubuntu-System:~$ sudo fdisk -l

Disk /dev/sda: 203.9 GB, 203928109056 bytes
255 heads, 63 sectors/track, 24792 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x07030703

   Device Boot Start End Blocks Id System
/dev/sda1 * 1 24792 199141708+ 7 HPFS/NTFS

Disk /dev/sdb: 82.3 GB, 82348277760 bytes
255 heads, 63 sectors/track, 10011 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e66f2

   Device Boot Start End Blocks Id System
/dev/sdb1 * 1 32 250880 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sdb2 32 10012 80164865 5 Extended
/dev/sdb5 32 275 1951744 82 Linux swap / Solaris
/dev/sdb6 275 1491 9764864 83 Linux
/dev/sdb7 1491 10012 68446208 83 Linux

Disk /dev/sdc: 640.1 GB, 640135028736 bytes
255 heads, 63 sectors/track, 77825 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00069f22

   Device Boot Start End Blocks Id System
androidba@Ubuntu-System:~$

Let me clarify that the above disk: /dev/sdc: 640.1 GB is the one that I installed Winows 7 and XP on. It seems that Ubuntu doesn't recognize Windows on that disk. Anyone can help me to set up a boot menu so that I can select which OS to log in, please.
Thanks,