Yesterday I’ve created a step-by-step tutorial on “How to Dual Boot Vista and XP with Vista Installed First“. Today I am going to show you how to dual boot XP and Vista with XP installed first. It’s a different scenario than yesterday. This time is you already have Windows XP installed which takes up 100% of the hard drive and you want to install Windows Vista on the same hard drive.

Configuring dual boot when you have XP installed first is way much easier than Vista installed first. Just follow the steps below on how to dual boot XP and Vista with XP installed first.


First things first, you need to re-partition or shrink your current XP partition to have free space for Vista installation.

1. Boot up your computer with Vista DVD. At the part where it ask you for product key, press SHIFT+F10 simultaneously. It will bring up command prompt.

2. Type DISKPART

3. Type LIST VOLUME

4. Select the volume where XP is installed by typing SELECT VOLUME 0. If somehow the XP volume is other than 0, then just change the number at the end.

5. Type SHRINK and it will automatically shrink your XP partition. Close command prompt and continue with Vista installation. You should install Vista on “Unallocated Space” when you get to the part where it ask you where do you want to install Windows.

Note: If you get an error message that says “Access is denied” when shrinking your partition with diskpart, boot up with Hiren’s BootCD and use either Partition Magic, Acronis Disk Director Suite, Paragon Partition Manager or any disk partition tools that you like to resize your XP partition. Minimum Vista hard disk requirement is 20 GB hard drive with at least 15 GB of available space.

Once Vista is installed and the system reboots, you’ll be presented with a boot menu with two options: “Microsoft Windows Vista” and “An Earlier Version of Windows”.

Booting to an earlier version of windows will boot up Windows XP. If you want to change the name “An Earlier Version of Windows” to Windows XP,

I found out that I can’t manually edit boot.ini file in Windows Vista. It gives me the error message “Access is denied“. I also tried going to Startup and Recovery from System Properties but there is no Edit button which allows me to edit boot.ini.

There are 2 free utility I found which is able to edit Vista boot manager.
1. EasyBCD
– Click Change Settings button, select Earlier Version of Windows from Entry-Based Settings drop down menu. You can change the text that says “Earlier Version of Windows” at Name. Click Save Settings.

[ Download EasyBCD ]

2. VistaBootPRO
– Click Manage OS Entries button, select “Earlier Version of Windows”, check Rename OS Entry and type the name that you want it to display and click Apply Updates.

[ Download VistaBootPRO ]

There you have it. Now you can have both XP and Vista in one hard disk.

P/S: If you’re looking for dual booting Windows Vista and XP with Vista installer first, click here.