Cant boot into linux install

I installed the latest version of Ubuntu on an eMachine that already had Vista Ultimate. The install partitioned the hard drive and everything went fine but the next time I booted up the computer there was no boot loader, it just went straight to Vista. Can I put a Linux entry in the boot.ini file? This is my first time intalling Linux.

You maybe installed grub to the boot sector of your root partition ( / ) and not the MBR. I've not installed Ubuntu but there must be a custom install method or something that lets you specify where to install the boot loader.

Are you able to boot from the CD again into a safe mode, command prompt, rescue mode, anything like that??

Phantasm66, you are right Ubuntu does have a custom install feature, all you have to do is set ubuntu to install the grub bootloader to the MBR.