If you want both OS you need to do a partition on the HD to proceed.IThat what i can figure from your quest.But if you just want XP just do a clean installation of it.
Perform a clean install of Windows XPA clean installation consists of removing all data from your hard disk by repartitioning and reformatting your hard disk and reinstalling the operating system and programs to an empty (clean) hard disk. For more information about important things to consider before you partition and format you hard disk and how to partition and format your hard disk by using the Windows XP Setup program, click the following article number to view the article in the Microsoft Knowledge Base:313348 (http://support.microsoft.com/kb/313348/ )
How to partition and format a hard disk by using Windows XP Setup programTo perform a clean installation of Windows XP, follow these steps:
- Back up all important information before you perform a clean installation of Windows XP. Save the backup to an external location, such as a CD or external hard disk.
- Start your computer from the Windows XP CD. To do this, insert the Windows XP CD into your CD drive or DVD drive, and then restart your computer.
Note To boot from your Windows XP CD, the BIOS settings on your computer must be configured to do this.
- When you see the "Press any key to boot from CD" message, press any key to start the computer from the Windows XP CD.
- At the Welcome to Setup screen, press ENTER to start Windows XP Setup.
- Read the Microsoft Software License Terms, and then press F8.
- Follow the instructions on the screen to select and format a partition where you want to install Windows XP.
- Follow the instructions on the screen to complete the Windows XP Setup.
If you have successfully installed Windows XP, you are finished. If these steps did not help you install Windows XP, go to the "Next Steps" section.