If you can boot into Ubuntu, you might give Boot Repair a try. I've used it several times and it works well. Of course, it requires that you Windows stuff is still there, and it probably is. The following text I copied from the Ubuntu Community Documentation:
ppa:yannubuntu/boot-repair to your Software Sources via the Software Center or, for speeds-sake, add it using a new Terminal session:
sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get
update sudo apt-get install -y boot-repair && boot-repair
Boot-Repair can be installed and used from any Ubuntu session (normal session, or live-CD, or live-USB). PPA packages are available for Ubuntu 10.04, 10.10, 11.04, 11.10 and 12.04.
Launch Boot-Repair from either :
- the Dash (Unity)
- System->Administration->Boot-Repair menu (Gnome)
- by typing 'boot-repair' in a terminal
Then try "Recommended repair" button. When repair is finished, reboot and check if you recovered access to your OS.