For your case, although Ubuntu was installed on the second hard drive, Grub should have been installed on the MBR of the first hard drive. So long as no hardware changes occurred, Grub should be able to locate your Ubuntu install.I highly recommend you try running Ubuntu in a virtual machine to get a feel for it before doing anything risky with your PC. Installing Ubuntu is actually straightforward in most cases, but if you're not confident about it, just hold off until you are. In the meantime, download Virtualbox (an EXCELLENT open source virtualization tool like VMware) and the Ubuntu iso, point the "CD-ROM" drive to the Ubuntu iso image, and boot away! When you maximize the screen, it will look just as if you booted into the real Ubuntu (well it actually is the real Ubuntu, just not on a real Linux partition).I hope this helps, and I hope you finally get it figured out. After you trial Ubuntu, try out Linux Mint and/or Mepis. They're strong operating systems that are very newbie-friendly, but still as powerful as Ubuntu/Debian (Linux Mint is basically Ubuntu with built-in codecs, and Mepis was the same until they went back to Debian roots).