and device.map
(hd0) /dev/sda

Ignore lines with a "#" in front as they are disabled and served as comment only. Your first bootable system has these lines
telling us the "root" of Ubuntu is (hd0,9) or in the 10th partition of the 1st disk as Grub counts from 0. In Linux term it is sda10.

According to the information in Post #3 this partition is sda10 because sda is your 1st disk or (hd0) to Grub. However sda10 is a Type 7 partition for NTFS filing system which Grub does not support (or it can't read it). Thus Grub complained that it couldn't mount it. As a rule Grub treats a NTFS partition as unknown partition. It can boot a system inside a NTFS partition by chainloading (indirectly) but not directly using "kernel" and "initrd" statements.

To obey the "kernel" and "initrd" commands Grub has to physically go inside (hd0,9) to read off the /boot/vmlinuz-2.6.20-15-generic and the /boot/initrd.img-2.6.20-15-generic.

Either you have edited the menu.lst or since installation reduced the number of logical partitions resulting the partition references no longer matching the current setup.

-------------------------------------------
The cure

edit the menu.lst to change (hd0,9) to (hd0,7) as follow
There is a good chance Ubuntu would boot now.

Thanks,very much now I in ubuntu!!!You rocks.
and one more thing...
I had star in sda1 and sda8 in my fdisk....what does that mean...and in which partition my grub is present... also where is my mbr stored....
Also I will install fedora 7....will it cause any problem??In which partition I should install that...
and last thing why chroot command didnt worked???
and again thank....

The star means the partition's booting flag is in the "on" position meaning it is active or bootable. Only MS systems use the booting flag. Linux doesn't need the damn thing.

You will find Grub is in sda8's /boot/grub directory.

MBR is the first sector of 512 bytes of the first boot disk in your PC. Whenever a Bios is asked to boot a system from a hard disk it grabs its first and loads into the memory and buggers off to a holiday. Whatever inside the first sector, also called superblock or MBR, controls the booting.

All boot loaders have two parts with the first part exactly 512 bytes long for occupation in the MBR. The first part will pull up its second part using the hard disk address hardcoded.

You can install Fc7, Fc8, Fc9....Fc9999 as far as Linux is concerned. It matters nothing as every Linux boot loader can multi-boot. You can put one Linux per partition for an easy life.

I have just noticed my recent Fedora has disabled "chroot" command too. I couldn't tell why but you can use any other Live CD and 99% of them can chroot.

The "star" (asterisk) is the bootable flag---it is not used by Linux

GRUB would normally be in the MBR--not a partition. If it IS in a partition, then there would also have to be boot code in the MBR (might also be GRUB).

The MBR is the first sector on the drive

To install Fedora, you need empty space on the drive. The installer will do the partitioning. Tell the installer not to install a bootloader---or, if it insists, tell it to put it on the Fedora partition. Then edit the existing /boot/grub/menu.lst to include an entry for Fedora.

If you do let the Fedora installer install the bootloader in the MBR, then you will need to edit the new menu.lst (on the Fedora partition) to include the other OSes.

The link below will lead you to an article on booting---and the links in Saikee's post are the ultimate authority.

pixellany,

You certainly know how to make a guy's face turn red.

I am just learning here and a lot of times from your posts too. It is nice to discuss the problems and see each other's view. You have been spending a lot of effort in helping many members with booting problems and makes this forum responsive and up to date.

I don't have your patience and only jump in if a thread has dragged on a bit.

thanks again...