You got the wrong bootloader going... iirc ubuntu overrides win bootloader with grub. maybe things changed. you can use easybcd but be careful. or run repair cmd, and its either fixboot or bootcfg /rebuild etc.. If you only care to have linux on the computer, and you want to wipe windows, then just wipe drive and install ubuntu fresh.
edit:
you wrote that you downloaded the software. do you mean that you attempted to install it as well?