Your mass storage usb driver has been corrupted. Go to control panel, system hardware, devices, usb mass storage device. Select update driver, follow instructions of installation wizard. Have your Dell drivers disc ready to insert when prompted. As a bit of insurance, set a restore point before doing this, in case you get a bad result, or just use the "rollback" feature of the update window. Good luck. This is an easy fix.
Running WinXP Home w/SP2 on a Dell Dimension 4550, I had used the front USB port for a camera without any problems. But when I bought a Lexar Jump Drive, my computer crashed when I plugged it in. I assumed it was the J-Drive, and exchanged it for a Kingston 128, which, oddly enough, worked for a little while. But when I got a Kingston 512, it crashed again. And plugging in a 4-port hub, I get the same crash. This is true for all USB ports on the machine. The Microsoft response pages I get (after "recovery from serious error") identify either: a device driver as the problem; or graphics device driver with a "STOP 0x000000EA_Thread_Stuck_In_Device_Driver" message.
I've already confirmed that Hardware Acceleration is set to None, but I don't know where to go from here. I have the Dell Resource CD with the drivers on it, but I'm not sure about using it without a little advice first about what NOT to do, etc. Can I just reinstall all the drivers, using Device Manager or something? Anyone? I'd be very grateful for any help!