Configure your PC to boot from CD if it isn't already set up that way. You may need to enter the BIOS to configure the PC to boot from the CD.
Set the boot order to
floppy if present
SAVE and EXIT
Start your PC with the XP Setup CD in the drive. When you see the "Press any key to boot from CD..." prompt, do so and let the CD-based boot process begin.
When the Recovery Console option is offered ("Press R to start the Recovery Console"), do so. You may be asked which Windows installation to enter, in which case type the number of the Windows installation you wish to work on (usually "1").
When prompted, enter the Administrator's password for that Windows installation. If you did not set a password just press ENTER
At the command prompt, type
The exact wording will depend on your setup, but after a few moments you'll see a prompt that says something like:
Total Identified Windows Installs: 1
Add Installation To Boot List?
Assuming the information you see is correct, enter
Bootcfg will start the process of rebuilding the boot list to include the indicated Windows installation
After a moment, you'll be asked to "Enter Load Identifier."
This is the name of the operating system that will appear in boot menus.
Microsoft Windows XP Professional
Microsoft Windows XP Home Edition
Next you'll be asked to "Enter OS Load Options."
For normal installations, enter
to leave the Recovery Console and reboot the PC