I took 60 photos at an event with my Canon Powershot on a SD card, all 60 copied to my hard drive but only 30 were able to open but the other 30 refuse to open or generate thumbnails. The data is there, each picture that doesnt open had a file size between 2Mb and 3Mb. Is there software than can 'repair' or 'open' these files?
Vulcan proverb: The good of the many outweigh the good of the few.
[ I took 60 photos at an event with my Canon Powershot on a SD card, . . . each picture that doesnt open had a file size between 2Mb and 3Mb.]
2-3MB files taken by a Canon Powershot sound more like movie files than photographs. I would expect a point-and-shoot photograph to be under a meg. What is the file extension on the images that wont open? If it is .AVI then they are movies; if it is .JPG then they are photographs.
[ Is there software than can 'repair' or 'open' these files?]
If the files are jpegs (.JPG) then any number of applications will open them, including the web browser with which you are viewing this page. If the files are .AVIs then there are a smaller number of apps that will open them, though one good one was included with your Powershot purchase, it is the ImageBrowser application. Another option is the QuickTime Player.
If the files are truly damaged then try downloading them again from the SD card, if you havent erased it already. It might just have been a problem in the download process. I would recommend a cheap card-reader as opposed to downloading from your camera, that way there are fewer avenues for problems.
If the images are corrupt on the SD card itself then you will have to run .JPG repair software to fix them. Chances are you lost the header information. DataRescue.Com has a product called PhotoRescue that should do the trick (www.datarescue.com/photorescue/index.htm); there are probably freeware versions of other programs that might work as well.