dual booting problem
 

see i first install windows vista ultimate and then ubuntu10.04lts in free space.then few days later i format windows vista and install windows 7 ,from that day dual booting option is not display during start up.plz tell how to recover dual boot option or how to recover grub file

This issue has been explained many times here.

https://help.ubuntu.com/community/Gr...0from%20LiveCD

You should use the web site search near the top of the page to look for similar problems before you post a problem. I found many listings when I searched for the phrase "restore grub after installing windows". One of those listings had the web page that I put in this post.

been there before
 

What is really happening is that M$ Windows doesn't like any other Operating System (OS) on the same machine. So, when you install/reinstall M$ Windows (XP,Vista,7, etc.) the boot section on the Hard Disk Drive (HDD) is overwritten. Therefore the bootloader will not see Linux. It's still there but you need to move off the M$ boot loader and install a more versatile loader such as LILO or GRUB that will handle both systems. This happens often with nubi's :>)

I have a simlar problem, but it is the other way round...

I installed Linux, attempted to partition it along side Windows.
On the partition manager it shows my Linux has 20gb, which i set it up to be. But my 100 odd gb of windows is coming up as unallocated, how to I either get my files from it or get it to boot from that?

I understand the question but don't understand. Please rephase the info and question. It may be that you swiped out the MS - - - don't know we need more info about what you did.
SORRY

I am assuming that you are using either Ubuntu 10.04 or 10.10 here. Is that correct?
Open a terminal (applications > accessories > terminal) and post here the output of: This will tell us what partitions Ubuntu sees. This way we will know if the Windows partition still exists and has not been reformatted.
If you get a NTFS partition listed in the out from fdisk, then try running from the terminal in Ubuntu: Hopefully that will add Windows to your grub menu so you can boot it.
Write back if you need more help.

Thanks
 

Thanks for your help with this, I've tried it all...
and came to the conclusion that it is gubbed! :)

I must have wiped it when installing :/

Thanks again!