I've got a Lenovo z560 Ideapad. Any time I plug anything into one of my USB drives (two different external hard drives, Kindle) it prompts me to scan and fix (which never finishes when I try). Things I plug in constantly disconnect and reconnect, and are sometimes totally unresponsive. Chkdsk tells me there are no problems with any of the drives, and I don't have any viruses. Any ideas?