Dual boot after a new installation on the primary partition. Will it still work?

Question

My current set-up:

• Master Boot Record: Grub installed, parametrized by Ubuntu 10.4
• First Primary Partition : Windows Boot Loader, and Windows Vista
• Second Primary Partition : Windows 7
• Third Partition : The Extended Partition.
• First subpartition of the Extended Partition : Ubuntu 10.4
• Second subpartition of Extended Partition: Swap
• Third subpartition of Extended Partition: /Home of the Ubuntu 10.4

But I will no longer use the Windows Vista and the Ubuntu 10.4. I am gonna install Ubuntu 12.4 (really nice GUI by the way), and keep the WIndows 7 already installed.

So what I am planning to have in the end:

• Master Boot Record: Linux bootloader (i don't know which one is in Ubuntu 12.4) parametrized by Ubuntu 12.4
• First Primary Partition : Ubuntu 12.4
• Second Primary Partition : Windows 7
• Third Partition : The Extended Partition.
• First subpartition of the Extended Partition : nothing, surely I'll extend the swap.
• Second subpartition of Extended Partition: Swap
• Third subpartition of Extended Partition: /Home of Ubuntu 12.4

Well, that's the plan. However I have a big fear before I start the irreversible thing.

If in my current setup, the current Windows BootLoader (that is called by my current Grub on the MBR) is located on sda1... then it will be deleted if I install Ubuntu 12.4 on sda1...

Is there a safe way to be sure that I will still be able to launch my WIndows 7, that will remain on the second primary partition, if the windows boot loader that was on sda1 is deleted ?

What can I do if I still want to run that windows 7 ?

Answer 1

You could do following steps:

1. Mark partition of Windows 7 as active (using Windows Disk Management or any other tool like Partition Wizard).

2. Download and install Visual BCD package. Run "Dual-boot Repair" utility and select "Automatic Repair" - this will recreate Windows 7 boot files on Windows 7 partition (which is already marked as active and write a Windows MBR also). At this point you could reboot and Windows 7 will be the only OS seen by Windows boot manager.

3. Install Ubuntu - this will write GRUB2 to MBR and create a dual-boot for Ubuntu and Windows 7