It can be inferred from what you say above that Grub is already installed in your usb pendrive and you wanted to boot linux in /by it. [If not yet you must install now.]
Also, I can understand from your english that this same usb drive worked well and booted already on your Dell laptop.
Now it doesn't work 1008HA. Something is wrong in the new bios environment. Maybe 1008HA doesn't allow booting from usb? until you set your pendrive into "active". So this time try check your /grub/menu.lst and put additional grub command after the kernel line:
Note: this is only a trick, so just try it. But my suspicion is high against the bios of your 1008HA.
If your new 1008HA cannot recognize booting directly from usbpendrive you can still boot from it under 1008HA by installing grub into the 1008Ha then modify the menu.lst provide an entry (on the grub on hard drive) to point to the usb drive in this manner you can still boot either from usb or hard drive of your 1008Ha. To be clear, this remedy has the following procedure:
1. Install Grub into the 1008HA hard drive.
2. Modify grub/menu.lst on the hard drive to have an entry for booting to usb. Modify device.map
3. Bios settings may always boot to the hard drive but an option is given to for the usb.
You must have sufficient working knowledge about grub. Reading this tutorial in few minutes will give you enough to do the job: http://www.dedoimedo.com/computers/grub.html
Hope this helps.