I assume you installed Ubuntu as a dual boot system, right? If this is the case, you can mount the Windows Vista partition under Ubuntu, then simply copy the needed file to the Ubuntu partition. First you have to check on which partition (or disk) Windows is mounted. Do
to find out. You should see something like this, among the lines:
/dev/sda2 913 10639 78132127+ 7 HPFS/NTFS
take note of the device (/dev/sda2 in my example, but could differ for you). Then mount it using
sudo mount -t ntfs-3g /dev/something /mnt
change /dev/something with the actual device. After that you should see the content of C:\ under the directory /mnt (the mount point) and you can copy files and directories as usual.