Try viewing them in IrfanView. http://www.irfanview.com/main_download_engl.htm
(don't use Download.com as they now force some kind of download manager on you)
If they are corrupt, restore them from your backup.
You might also want to run a chkdsk /r. Start > Run > chkdsk /r > OK or enter > Chkdsk cannot run because the volume is in use by another
process. Would you like to schedule this volume to be checked the next time the system restarts? (Y/N) > press Y > reboot
Edited by .X., 01 September 2011 - 08:35 AM.