While you have the SATA drive set as the main boot device, do you have it listed before all other items (floppy / CDROM, etc) in the BIOS? There are two places where this can be set - boot priority and enabled boot device order. I've run into this same problem myself on a number of occasions - just keep playing with the settings (jumpers, BIOS configurations, etc) until you get it. I have a feeling that for some reason, your SATA controller is no longer the priority boot controller, but the IDE controller is. Usually IDE is the default priority controller and SATA is secondary - if it encounters a drive on the IDE controller and can't boot it, it presents you with the "insert a boot CD" line. If there is no hard drive on that controller, it skips it and goes to the SATA controller. Sounds like Alienware was lazy (not to dis your new system, but this is really no surprise, the quality of their stuff has really decreased over the past year or two and their support services are absolutely useless) and didn't setup your BIOS properly when it left the shop. That leaves it up to you to set the priorities correctly in the BIOS.