I was going to suggest that you turn off and restart the computer, with the camera plugged in and on, so it would be mapped at startup as a drive. I wonder if you left your card in the reader if it might be recognized at startup?

Windoze may need a little help recognizing all of your drives. Did the computer come with the card reader, and did you install all of the computer's drivers when you reinstalled Windows? If you installed the card reader separately, you may need to manually reinstall it again with the CD it probably came with.

SRS