This is for others who may run into this problem with external hard drives:
I went to load up my EHD with my photos (over 300gigs worth) and it wouldn't load, it kept giving me "error performing inpage operation". Now since I know a lot of us shoot digital and store on EHDs, here's the solution.
Click RUN and cmd then you'll be in command window - then type chkdsk [drive:] /F (such as - chkdsk e: /F) which should perform a repair.
You can't get Check Disk to run like you usually would and you gotta do it that way.