If a desktop, open the case and disconnect power and cable from the card reader device. Physically removing the device will accomplish the same thing, but leave you with an empty hole in the front of the computer.
Maybe drive I (i) is not good. Drive letter for that drive will change once you disconnect the power for the card reader; shut the computer down first, unplug the power connection to the card reader, then start it back up. Unplug and reseat the connections for the slave drive before powering back up. Check to make sure your slave drive is either set to cable select or slave when installing it.