I tried to install in my laptop Ubuntu 12.04 so that I can dual-boot with Windows 7. I made some mistakes during this process and I didn't manage to install Ubuntu. But my real problem now is that I'm afraid that I also destroyed the installation of Windows 7. Your help would be precious for me.

Here are the details of what I did:

1) I followed these instructions to dual boot Ubuntu 12.04 and Windows 7:

http://www.linuxbsdos.com/2012/05/17/how-to-dual-boot-ubuntu-12-04-and-windows-7/

The only difference from what is described above, is that in my case the device names where: /dev/mapper/isw_fdjdhbadc_Volume0* instead of: /dev/sda*

Note that I had created a bootable USB stick to do that.

2) The installation proceeded normally, but in the end I got a fatal error because the grub-install failed.

3) Then, after googling this problem, I runned ubuntu from the USB stick and run this command:

sudo grub-install --root-directory=/home/ubuntu/temp /dev/mapper/isw_fdjdhbadc_Volume0p5

(/isw_fdjdhbadc_Volume0p5 was the partition that I had made for /boot)

but this command also failed.

4) Then, I did something stupid (I think): I run the above command as:

sudo grub-install --root-directory=/home/ubuntu/temp /dev/mapper/isw_fdjdhbadc_Volume0

namely I tried to install grub in the device isw_fdjdhbadc_Volume0 instead of the boot partition isw_fdjdhbadc_Volume0p5

The above command did not fail and was executed ok.

5) After that, I tried to boot my laptop, but it seemed that I had no operation system. Not even windows were detected.

6) I thought that I should uninstall grub from isw_fdjdhbadc_Volume0. So following some online instructions that I found, I booted again Ubuntu from the USB stick and run the following command (this was stupid since the instructions were for a totally different case than mine):

sudo dd if=/dev/zero of=/dev/mapper/isw_fdjdhbadc_Volume0 bs=446 count=1

Afte that, I was still unable to boot Windows. I realize that I deleted something that I shouldn't, but I'm hope that this is not crucial and I can recover somehow. When I boot Ubuntu from the USB, I can see that the partition with Windows is still there, with all the directories, Windows files, my data etc.

So, my question is: Is there a way to undo the mistakes that I desribed above and recover Windows 7? This is my major question. After solving that, I'd also like to know what I did wrong with the installation of Ubuntu.

Thanks in advance for you valuable help!