Ok, so there we are. You have downloaded the ubuntu live cd, and you are on the desktop.
I run it into virtualBox, which allows me to take screenshots along the way, and I will use a windows 98 disk to play with.
Now, go in the top menu named "system" and choose "administration" => "partition editor"
If you have several disks, you can see them in the top right corner of the application.
Every IDE disk will be labelled HD{something} and every SCSI or SATA disk will be labelled SD{something}
"Somthing", in that case, will be a letter. Starting from a to z, which identify your hard disk.
So, for instance, the first partition of the primary master IDE disk will be HDA1. The secondary partition: HDA2 and so on...
Okay, so you have now located your hard disk, and the partition editor should be shownig you the partition table curerntly attributed to that disk
Of course, yours will certainly show something different.
Now, select every partition you want to delete, one by one, by clicking into the central part, just below the "new delete | resize/move ..." toolbar, and once the partition is selected, click "delete".
Once every partitions are discarded, click on the gray area, and choose "new"
Keep the default options, except that on the "filesystem" option, choose "ntfs", and click the "add" button.
Once all this is done, click the "apply" icon, left to the hard disk selector to save your changes, confirm the actions and reboot your computer (on the top left of the screen, there is the logoff/shutdown command).
Then, the windows XP installer should be able to see an empty partition and use it to install itself.
If not, a supplemental step might be necessary (but it can take a lot of time, depending of your disk size), so if this is not enough, tell me and I'll give you another tutorial.
