does anyone know if it is possible to (step by step):
> create another partition on my hard drive
> change the original partition (that win xp is on) drive letter
> change the new partition drive letter to c
> change the new partition to the primary/system partition
> do a clean install of windows xp home from the disk on the new hard partition whilst still having the old one on a different partition
> get some free software that allows me to choose which partition to run on startup
??
(so basically i'm left with 2 installs on xp on different partitions of the same hard disk)
you can use Partition magic to split an already OS installed drive.
but you should always back up beforehand, and its always better to install a partition to a fresh formatted drive.
you can use your HDD disk tools for this.
Disk management can change drive letters you can access this in Administrative Tools > Computer management inthe accessories section
Well the andyman,
What you want is very simple to do. What you will need is Acronis Disk Director Suite*, Nortan Partition Magic*, or anything that can split and make new partitions.
1.
Backup before doing anything, you don't want to lose valuable data.
2. Open your partitioning software and create a new partition by making the current one smaller, and using the left over space to make a new partition.
3. Reboot your computer and make sure the partition is working fine and is formated.
4. Pop in your Windows XP cd and restart your computer. Pick the newly created partition and install there.
5. After the very long installation, you should have the new partition working with Windows XP, and have that one has your main boot up partition. As for boot manager software I have no clue, sorry.
Hopefully this will all work and I will search for some boot manager software.
*You must pay for these programs, try to find some warez or an alternative. I am not giving any info on the forums 
well i've got some disk that i got from my work experience that when you run it and type pqmagic in the command line it runs a partition thing (so i pressume its 'partition magic')
i also have acronis partition expert which i run from within windows, and i've used windows disk management before
hmm, i'll have a think about this - i don't think i even want to do it anymore