Each time I insert a USB flash drive into my computer, it starts (re-)installing some HP printer drivers. It occurs with two different USB drives, and appears completely unrelated to the contents of those USB drives. Any tips on how I might track down what is happening?
I suspect what's happened is that HP have managed to register their driver as the driver for USB mass storage devices. You might be able to fix this by finding the .inf file relating to that driver and deleting all copies of it, but that will prevent the drivers from working with printers as well.
(Remember to back up your system before trying that...)