When I took the test, it was some pretty standard stuff in the OS parts. If you feel uncomfortable downloading one of the many thousands of PDF's or guides, there's also many free sites to help you. Even one of those "Basics of Computing" books/sites could help you out, the more leaning toward MS operating systems the better.
Let me tell you now, learn the basics of printers. There were more questions about printers than there should be on that test.