grub2 - Dual boot problem! (GRUB PROBLEM)

Possible Duplicate:
How can I repair grub? (How to get Ubuntu back after installing Windows?)

I had just finished my setup for dual boot, everything went fine but I lost my ubuntu:

• zero fill + create 2 Windows partitions (FINE)





• Install Windows and configure C:/ for The system and D:/ For documents (FINE)




• Create 2 partitions for Ubuntu, one for the "/" and other for SWAP (FINE)




• Reinstall windows on the C: test, if I ever need to do that, FAILED, now I just have Windows on the boot, I lost that option to launch either windows or ubuntu.

How do I fix that?

EDIT: Just googled a bit and some people say it's a grub problem

Please help me =/