Windows XP Cannot change drive letter of system reserved partition??

Hi,

I finally got xp installed to my laptop, however, I have run into a problem. The software I want to install is designed to only be installed to the C:\ partition, it will not let me choose another drive to install to and I cannot install to C:\ becauase there is not enough space to install the software to. My computer is seeing the system reserved partition as the C:\ and windows 8 is on D with windows XP on E..

I thought it would be an easy fix to go to the Disk Management application in Computer Management and change C: to say P and then change my Windows XP install from E to C satisfying the need for space however it wont let me change that letter on account of it being a system reserved drive. Is there an easier way than having to prat about installing yet more software for partition management to shrink Windows 8 and therefore allow my to increase the space of C?

Furthermore, do you know how I can fix the boot loader so that I can get access again to the windows 8 installation?

Thanks in advance.