Hi,
You cannot install Windows XP on Partition D as it is the recovery partition.
The easiest way to configure a Windows XP/Vista dual boot system is to format the entire drive, make more than two partitions, install Windows XP on the first partition first and then install Windows Vista on the second partition. However, after doing this, you may lose the preinstalled Windows Vista and the recovery partition Dell provides to you. If you do not have a Windows Vista retail disk and would like to keep the recovery partition, you may need to try the following method:
1. Shrink a partition from Partition C and name the shrinked partition as Partition E.
To shrink a partition, you can refer to the following article;
http://www.howtogeek.com/howto/windows-vista/resize-a-partition-for-free-in-windows-vista/
Please Note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.
2. Install Windows XP on Partition E.
After that, it is expected Windows Vista cannot boot. You can try the following steps to make it boot again:
3. Boot into Windows XP.
4. Insert the Vista disk into DVD-ROM.
5. Click Start, click Accessories, right-click the command-prompt shortcut, and then click Run as Administrator.
6. Type the following command at a command prompt and press Enter:
Drive:\boot\Bootsect.exe /NT60 All
In this command, Drive is the drive where the Windows Vista installation media is located.
Note The boot folder for this step is on the DVD drive.
4. type the following commands at a command prompt and press Enter.
Note In the commands below, Drive is the drive where Windows Vista is installed.
Drive:\Windows\system32\Bcdedit /create {ntldr} /d "Windows XP"
Drive:\Windows\system32\Bcdedit /set {ntldr} device partition=e: (Note: e: is the drive letter for the active partition) Drive:\Windows\system32\Bcdedit /set {ntldr} path \ntldr
Drive:\Windows\system32\Bcdedit /displayorder {ntldr} /addlast
3. Restart the computer.
For more information, please refer to the following article:
Windows Vista no longer starts after you install an earlier version of the Windows operating system in a dual-boot configuration
http://support.microsoft.com/kb/919529/en-us
However, before doing the above steps, I suggest contacting Dell of more information first.
Hope it helps.
Tim Quan - MSFT
