Dual Boot: Windows 7 with existing Windows Vista

Most of our users are using Windows Vista as the primary operating system and a lot many of them now looking forward to upgrade to WIN7 Beta. The Windows Vista image loaded on the laptop often creates only a single big partition that has all the Windows files/folders and users data. Now, if a user wants to install Windows 7 Beta, he / she have to install using the upgrade method.

There may be scenarios wherein, users may like to retain existing Vista OS, for testing / application compatibility reasons, in this case users can follow the below steps to have dual boot options without disturbing their older operating system (say vista), just by creating a new partition and then install Windows 7 onto that partition. By doing so, users can have Windows Vista on the first partition and can have Windows 7 onto the second partition.

Steps to Follow:

Step 1: Start Windows Explorer. Right click My Computer and click Manage or click Start -> Run -> compmgmt.msc


This will start Computer Management MMC Snap in.

Step 2: In this screenshot you can see there is Disk 0 with capacity 149.05 GB

There are two partitions

First Partition – BitLocker Created system partition 1.46 GB

Second Partition – Windows Vista of size 147.59 GB

So, in order to install Windows 7 we need to have another partition. We will now create a new partition on which we can install Windows 7.

Note: In some cases you may not find the first partition i.e. BitLocker Created system partition. This is created when you have deployed the MS IT BitLocker Supported Image or users have run the BitLocker Preparation Toolkit on their machine.


Step 3: Right click on the C: Drive i.e. 147.59 GB and click on Shrink Volume


Step 4: Select the amount of space to shrink in MB, below by default selected approximately 74.5 GB. Users can select more or less size depending upon their needs, Click Shrink. This will create new partition with unallocated space


Step 5: Right Click on the unallocated partition and click on New Simple Volume.

This will launch New Simple Volume Wizard. Click Next.


Step 6: Specify Size. We will keep it 30000 MB (30 GB). Click Next.

  • In the assign drive letter option select D or E (depending upon the free letter, G in this case)
  • Click on Next
  • In the Format Partition Select Volume Label and select Perform a quick format option.

If users need, they can change the default Allocation Unit Size or Enable file and folder compression.


Lastly, after the wizard is completed, it will show a brief summary of the options selected. Click on Finish, this will create the new Primary Partition of 30 GB with the selected Label and Drive letter.


Step 7: Now, pop in your Windows 7 DVD and boot the computer from DVD. At the time of installation select ‘Custom Installation.’ Select the newly created partition to install Windows 7.

Ignore the remaining unallocated space that we did not utilize. Click on Next


After the installation you will see Windows 7 as default OS and also the Windows Vista entry in the Windows Boot Manager.


Enjoy Windows 7 dual boot with existing Windows Vista