whenever i have either my western digital 80gb usb harddrive or a usb jumpdrive inserted and try to boot my winxp machine will not boot. i have tried to correct this by accessing the boot sequence in cmos but everything there looks in order. thanks in advance for any suggestions.

"Will not boot" means what?

What does the boot sequence look like?

usb harddrive / jumpdrive boot error

it freezes on the motherboard splash screen - if i unplug the drive(s) from from the usb port the box continues to boot up and windows loads

Do you have any USB devices defined in your boot sequence in BIOS? If yes, take it out. You can also disabling any "legacy USB" etc options in BIOS setup.

Many BIOSes clam to have boot support for USB devices but it is almost always incomplete and dodgy. Only (some) laptops manage to do it right in my experience.

usb storage devices prevent boot up

right on - i already tried disabling everything in my boot sequence except my floppy, one cdrom and my primary master hdd - still won't boot if those devices are plugged in.