Strange Issue About Multiboot(ubuntu+vista)

Hello Guys How Are You All …
i Have One Hard Drive (WD.320 SATA)
i Devided It To Several Virtual Drives (Partitions) C,D,E,F,G And A Left 15GB For Ubuntu (ext3)
i installed Vista On C:\ (OK)
i Installed Ubuntu On the left space (formatted ext3 and a swap area) Worked (OK)
i Was Having a Very nice dualboot smooth with no problems
BUT
When i needed to Re-install windows vista to have a cleaner environment : i formatted Drive (C:\) and Installed Windows vista .. everything for now is ok
i finished installing Restarted my Computer ,,, BOOM Ubuntu Disappeared from the booting list (only vista starts automatically)
some one told me that formatting C:\ Drive will make all the Boot data vanish (i hope some one tells me whether this is true/wrong info) and i need to know a way to protect my self from having such problem
Answer #1
There’s a sector of your hard-drive called MBR (Master Boot Record).
On this sector there are several information about the contents of your hdd – one of which is the instruction from which partition should the computer search information to boot from.
When you’ve installed Ubuntu for the first time, a little program called GRUB was installed on your MBR. This application, which is automatically configured at the end of Ubuntu’s installation “sees” both Windows and Linux installation and allows you to choose from what partition you would like to start your computer from.
When you reinstalled Vista, you’ve swipped all the information of the MBR and installed Windows boot manager. This boot manager does not “see” or configure itself to boot from anywhere besides from partitions which have Windows installed on the (XP or Vista). So, when you did so, you lost Linux’s boot information.
What you’ll have to do is to reinstall GRUB and reconfigure it. It’s not an easy fix, but I’m sure you’ll find a lot of information at Ubuntu’s forums. Here’s an HOWTO that will work:
http://ubuntuforums.org/showthread.php?t=24113
Answer #2
yup rite advice.besides the ubuntu forums are super active and ull get yur prob. sloved in no tym!!!
Answer #3
Thanks Guys REALLY i Appreciate Your Help All Of You And Your Care Thanks a Lot
Answer #4
It's not an easy fix
Not hard at all. Providing the entire drive wasn’t formatted and the linux install is still present on the partition.
Boot off a linux live cd.
Open up a terminal and su to root.
If you have a problem becoming root with Ubuntu,use a different linux live cd and be done with this already.
Ubuntu hides the root user by default,and if you don’t already know how to become root in Ubuntu,it is easier for this purpose of reinstalling grub to just use any other linux live cd.
After you have become root,then type at the prompt grub
That will open a grub shell.
Then type this command find /boot/grub/stage1
It will look like this.

Although I have several entries from the above command,I already know the entries that were written to the MBR on my drive that grub used are from hda5(which is hd0,4 in the screenshot).
That is the my “master” grub install.
(If you also already know which partition linux is installed to,you can skip this step)
You most likely have only installed one linux distro installed to your hard drive,(and that will be your “master” grub),and you will only see one result instead of six as my screenshot shows when you type the command find /boot/grub/stage1.
Use that entry that you get to replace hd0,4 in the example below.
Then…..
type in the terminal root hd0,4
(That command is telling the grub shell to use the files found on /dev/hda5)
type in the terminal setup hd0
(This is telling the grub shell to install those files to the MBR)
You will see some text scroll by,and then it will say it has successfully installed grub to hd0.
Reboot and you have your grub boot menu back.
EDIT:
To exit the grub shell type quit
Then you are back to the bash terminal.