1) First which version did you install. (The server edition has no desktop!). Did you install the LiveCD or the Alternate CD
2) Secondly which method of install did you use? It is better to use the Text install. If it says "username@ubuntu:~$" and you have not yet established a username and password it look suspiciously like you used the oem install.
3) If you have used the oem install try username:oem and password  either) oem (or) [blank]. The oem process is not finished until you run the command Then it will ask YOU for YOUR username and password and remove oem.
4) To get X run the command Quote: |
sudo dpkg-reconfigure xserver-xorg
| This will start a text-based wizard which will ask you some questions. If you don't know any answers than go with the suggested default. If at first you don't succeed then try again. If it still doesn't work then go with VESA. At least that should start the gui. |