I had only ubuntu installed on my pc, but I felt like adding another ubuntu (same version) partition so I could have one just for work/study and another one just for personal generic use.

I installed it and it worked out okay, but I found I needed more space on the new created Ubuntu partition, so I booted up from the Live CD, and used GParted to move/shrink/grow the partitions as the Ubuntu's tutorials suggested it was pretty straightforward. But in doing all this I messed up with Grub, so when I start my system it shows:

error: unknow filesystem grub rescue>

What would be the easiest way to recover it so I could have both partitions working? Btw, it wouldn't be a problem for me to lose the partitions if it's the shortest/easiest way.

Thanks in advance.