Boot your computer, enter your BIOS by pressing the key it tells you to press at the first splash screen you come to at startup, put the CD/DVD drive first in the boot sequence, insert your LiveCD, then save the changes, and exit your BIOS.
Your computer should now boot from the CD.
In the Ubuntu setup program, select the preferred language you use, then select the "Try Ubuntu with No Change To My Computer" option.
Once at the Ubuntu desktop, in a Live session, open up Applications->Accessories>Terminal.
Run:
% sudo fdisk -l
% sudo mkdir /win
% sudo mount /dev/sdxy /win