cannot read sorce disk

[frank po,etta]

I backed up my files on my computer now when I try to get some off it says cannot read source disk with about 1/2 the files if I look at them it say they are there and gives how big they are, but if I do a properties or try to copy it they say cannot read source disk. Any answers? of how I can get the files I copyed the files with easy cd creator iomaga v 4.01

thanks for any help the files are tax files thats why i need them