It might not be that simple.
Although Windows will report two partitions, there might be more hidden partitions using up the maximum of four primary partitions allowed.
I would go about it carefully. First of get the list of current partitions (boot to the LiveCD):
(That is a lowercase L by the way)
If this shows less than 4 primary partitions then good to go (otherwise stop and post the results here).
Boot into Windows, disable virtual memory, reboot then delete pagefile.sys if it is still there.
Run defrag to consolidate the file system (parts might be scattered all over the partition)
Once defrag completed, reboot to the LiveCD.
Fire up Gparted and shrink the Windows partition, leaving unpartitioned space.
Reboot to Windows, let it run through its checks, then re-enable the virtual memory.
Once happy that it is all OK with Windows, then re-boot to the LiveCD and install Ubuntu into the unpartitioned space.
We can walk you through this or you could have a go on your own.