Why is my PC boot time slow when USB HDD attached?

Usually this is because the BIOS is searching your whole drive for a boot sector that it can latch onto. You can sometimes upgrade the BIOS to make it a bit faster (usually just makes it give up easier). The other option is to remove the "removable device" from your BIOS boot order, or place it below your normal HDD.

I had the same problem on an HP desktop. Almost 3 minutes to simply arrive at the Windows splash screen, vs 15 seconds without the USB attached. There are no BIOS settings which force the computer to ignore the attached USB drive. But I discovered a simple solution- purchase a USB hub (I bought a Belkin) and plug the drive into the hub, and the hub into the computer. Problem gone!

Some BIOS versions allow you to specify removable media as one of the boot devices. If you remove this from the bios boot order, the system should ignore the USB drive while windows loads.

"Sadly the Toshiba Satellite (A200) is the same.

If there is a USB drive attached then don't bother with a boot, disconnect the drive first.

The only advantage of the hub is that you can disconnect all drives (connected to the hub) at once - hardly satisfactory."