Windows 7: I have dual boot Ubuntu 11.04 and Windows 7 and now i cant boot Window

I have dual boot Ubuntu 11.04 and Windows 7 and now i cant boot Windows it says Windows can not start the installation process.

The best two ways of running Linux with Wondows on one Hd drive.
Dual Boot Windows 7 and Ubuntu
Linux - Install on Windows 7 Virtual Machine using VirtualBox

Only My ubuntu works now my Windows wont even start up no more

Your post is pretty vague. Did something happen? Do you get the usual boot screen? What boot manager are you using? Something besides "it's broken" would give a clue.

edit: you may have better luck on this forum:

http://ubuntuforums.org/showthread.php?t=378694

Im using GRUB and i get to the usual grub boot screen when i try to boot Windows it boots then it checks the drive then a pop up pops up and says Windows can not start the installation process.

See my edit above. Most of the Linux-ites are familiar with Windows. The percentage the other way is a lot smaller. More people who have solved your problem are likely to live on a Linux board.

I didnt get the understand the link but u suggest i install Windows7 on top of linux instead of reverse.

If you have 2 HDDs on your system, install them independently - one on each HDD whilst you disconnect the other HDD during the installation. Then you switch between the systems with the BIOS boot order.

That is a lot easier way and you can handle both systems completely independently. Else there is always trouble with the Grub.

No, what I'm saying is just about everyone who deals with Linux has had to deal with Windows. It comes preinstalled on a lot of machines. There aren't as many Windows users familiar with Linux. Try both avenues. But I think you'll find a higher percentage of multiple OS types on Linux forums than on Windows forums. It increases your chances of getting a solution.

Your post is still meager on details. You don't save how many physical drives you have and what type. If you can't be bothered to fill out the system spec form then I'm not inclined to wrestle it out of you. Guessing games are a waste of time.