secdroid: I trust you have (according to this advise) put 'Removable' as the 'First Boot Device'. You might want to (as a way to be independent of this setting) select the boot device on a one-off basis: during the boot phases of most BIOS an option exists to select the boot device just for that one session (on my systems that is typically achieved by pressing the 'F12' key and then selecting a device, but YMMV).
I was testing by using the "F12" at boot method. Under "Removables," BIOS showed two options: Floppy and the USB stick as USB-ZIP0. I selected the usb stick and got "Boot error."
When I googled for answers, I saw comments to the effect that 530/531s were problemmatic, but I also saw comments to the effect that post-2006 Dell BIOS should boot USB-HDD. Maybe not. (Last time I buy a Dell; will build my own using quality mobo vendor next time.)
Furthermore on (older) systems that don't support booting from USB via the BIOS I've achieved good results with the help of the Plop boot manager. You could use this as a primary or secondary boot loader and then configure it to boot from USB as it's default setting. For example I own two older notebooks that still have a Win2000 or WinXP system installed on their hard disks and therefore use the 'NTLDR' mechanism as their primary boot loader. I now use 'Plop' as a secondary boot loader after adding it to the 'c:\boot.ini' file. That way it does not "upset the apple cart", but is available if I want to boot from USB.
Thanks for the suggestion. I noticed that Plop was mentioned in one of the TC help files and I skimmed the Plop documentation.
I had tried Plop with a circa-1995 laptop in the past and it didn't work for me, but I didn't have another way to verify my USB stick at the time. The Acer netbook is helpful to ensure that I have a properly-configured stick, so Plop deserves another shot. Might even give the old notebook another go at USB booting, even though it has a working TC install.
I had hoped to avoid Plop on the Dell as I have multiple boot loaders due to adding a second disk with Windows Server 2008 which, in turn, added a BCD-based boot manager to my /dev/hda GRUB which had booted my Linuxes and Vista. I currently have the MS BCD BM chained from my GRUB.
Looks like it might be prudent to look at moving GRUB off of the /dev/hda MBR to a Linux partiton, figuring out where to put Plop, and working with BCD Editor to try to make it all work. Shouldn't be necessary, but looks like it is. Messy.
Thanks for the pointers. I really want to move from CDs to USB sticks on the Dell, if at all possible.