then your set to go as mckee said earlier
sudo apt-get update
sudo apt-get upgrade
i would also install ssh sudo apt-get install ssh
if you get sudo isnt found error
reboot the machine and on startup hold the tab key, this will take you to the grub recovery screen, you will see your windows install there as well, but ignore that for now :)
scroll down to recovery and then select check file system, this will mount the system /rw , then select login as root, you can then add yourself to the sudoers group
adduser sudo whatever your name is or it could be adduser whatever your name is sudo sorry its been a while from ive done it
reboot the system and it should go to the grub screen again, select ubuntu or windows, you may get a windows mbr error
let the updates run it might take a while depending on the speed of the pc and and internet connection