I have an Alienware X51 R2 which I bought about 4 years ago. I have always had a problem that it won't boot when my external hard disks are connected during boot. If the disks are connected then it just hangs on BIOS boot. I see the picture of an alien on my monitor - but it never boots. If I unplug all the USB drives and boot - it works fine. I didn't set "Boot from USB" as the priority option in BIOS settings. Any idea what is causing this? Thanks..
that is a common bios issue w legacy XPS and AW model well known in R1. Basically bios takes a very long time or seemingly forever to do power on firmware test of certain usb devices connected to system. Your external hdd is probably causing a huge stalling of POST, thus alien head logo stays on screen forever. No get around the issue other than unplugging as many usb devices as possible (or mod bios). It is not a boot issue. POST stalls not because it is booting from usb. You have not even reached the boot from OS stage. Machine is still checking basic firmware to prepare for next stage which is boot. It is like before the restaurant opens for business it is still checking all the stoves in kitchen are properly working.
You should be able to bypass this. Enter bios, f2 on startup, boot, set boot priority, then disable usb boot support (option before setting hdd boot priorities).
Thanks. I had 4 USB drives connected and it seems to be a never ending process (i.e. overnight and it's still not done). To make things simpler I have now moved all my drives to a single hub so I can unplug only 1 usb cable when rebooting.