can't change boot sequence
 

Absolute beginner, would like to change to Linux. Downloaded Mandrake Linux 10.1 and transferred the three files to DVD. Have tried to change boot sequence on laptop and desktop (Windows XP) to read from CD/DVD drive first. Selected 'save and exit' but both machines still start up Windows XP. Can anyone help in plain language please?

Open the DVD in Windows Explorer. If you see three *.iso files, you burned the disc incorrectly. Typically you need to "Burn Disc from Image" with whatever burning software you're using instead of just dragging the files to a data CD.

EDIT: also, you'll only be able to put one image on a disc unless you go through a complex procedure to combine them. Try downloading the DVD from here.

Thanks, that worked. But now I have an error message in partitioning! It says 'I don't know how to format sda6 in type ext2:vfat' Any clues?

During the install, I assume that you are being prompted for how to set up partitions and to format them. The normal practice is to have a menu of choices for the format. ext2 and vfat would each be a choice, but they make no sense together.
Can you tell us more about the choices you were given during install?

yes, partition prompting. The DrakX Partitioning wizard offered - 'use existing partitions', 'Erase entire disc' and 'Custom disk partitioning'. The first of these brings the error message (now ' I don't know how to format sda15 in type ext2:vfat'). If I try 'custom' and 'Auto allocate' it says 'nothing to do'.

Well, for linux, you don't want to format anything vfat for base system. Linux doesn't live on vfat partitions. Most people use ext3. Now if you're dual booting with Windows, you will want a vfat partition to share files with windows, but you can create that later.

Sometimes it is necessary--maybe even desireable--to "wipe" the disk before setting up a new configuration. One popular tool for this is DBAN:
http://dban.sourceforge.net/