Try the Micro$oft Support article
http://support.microsoft.com/kb/314458
How to Remove Linux and Install Windows XP
SUMMARY
This article explains how to remove the Linux operating system from your computer and install Windows XP. This article assumes that Linux is already installed on your computer's hard disk, that Linux native and Linux swap partitions are in use (which are incompatible with Windows XP), and that there is no free space left on the hard disk.
Hope that helps.
RC