Originally Posted by cremedies
You cannot stop this message. You receive this error because Windows is currently in use. You have to use the Windows XP CD to do a format. Insert the CD, then reboot your computer. During the setup, you will be given the option to format the drive and reinstall your operating system if you wish. If your system does not read from the CD rom drive automatically, then you will have to change the boot order in the bios to set your CD rom drive as the primary boot device.
I hope this helps.