error loading operating system

[MJDBatista]

Hello,
my Acer Aspire One netbook has Kubuntu and Windows Xp on dual-boot. I intended to make another partition to install another O.S. But something went really wrong and can't boot the netbook anymore. I've tried a Ubuntu live CD, a Windows installtion Cd and UBS, and Hiren's Boot Cd, but keep getting the same message: "error loading operating system".
Does anybody have an idea? I don't realy care about the data in it, just want it back working.
Thanks.

[TheFu]

We need some facts please: https://help.ubuntu.com/community/Boot-Info will explain how to provide those.
In the meantime, you can google out "Boot Repair Ubuntu" and give that a shot too. It has fixed many booting issues for me and my systems.

[MJDBatista]

I could boot from a Ubuntu live CD (it seems the first one I used wasn't good) using "try Ubuntu" option and installed Boot-repair (https://help.ubuntu.com/community/Boot-Repair). Then I've created a Bootinfo summary from which I understood my partitions where damaged. From the the "Try Ubuntu" session I've installed Ubuntu, creating the necessary partitions.
I've got my netbook back workinh properly.
Thanks for the help.