ok
ill step by step this ok?
1) go to bios and set dvd drive as first boot option
2) boot into the dvd
3) click install or run a live (working from the DVD) system where you'll find the installer on the desktop. The advantage being you can test all the hardware first just in case and take a look around while it installs.
3a) Choose language, keyboard and region for the clock. do not hook up to the internet unless you have a very high speed connection or it will update everything during the install and that can take time. It'll offer updates later and you can use the system while it is updating so there is no inconvenience.
When it offers to install Ubuntu by using an entire drive or side by side windows xp
4) click do something else
5) find the other hdd, (it should be unformatted or it should have no data)
6) click the hdd
7) on the bottom left of the box with the list of hdd there is a minus sign, click it (MAKE SURE YOU HAVE CLICKED YOUR 2ND HDD FIRST!!!!!!)
8) then afterwards click the plus sign
9) then chose to have it formated in ext4 and in the box with the multiple choices, chose the one with "/"
10) accept
11) click install
12) your system is installing
13) it should have a grub menu showing windows or ubuntu
14) TADA!!
If it doesn't see windows at the next boot don't worry, that's an easy fix. If you are unsure which is your windows drive while installing cancel the install, shut down the computer and unplug the windows disk, and restart from the DVD, we'll add it back later but the original is faster if you are sure.