JPEG problem

Hey.  So, i was recovering files from a pooched hard drive, when i noticed something funny.  I just got a bunch of my JPEG files back, but when i looked at them, they were small, like the size of thumbnails.  but, when i looked at how large they were, they were anywhere from 650kb to 2 megs.  the software i used must have fucked up their proportions somehow.  i tried using a hex editor and changing the width and height, but that didn't seem to help (probably because i have no idea if i changed them in the right place...)  so do you guys have any ideas on getting them back to (relatively) normal?

photoshoop.

JPEG files generally include thumbnails in their EXIF data. That's probably what you're looking at, not the actual image.

alright then - how can I mke it so that they open the actual image data in any program i open it in, instead of it thinking the thumbnail part is the image?

... so that's a no then...

Find out what's the standard JPG image header in hex and search for it in your files. If every file contains that string you know where the original file starts. If you're lucky the rest of the file belongs to the original one so you can remove the data before that point, otherwise try looking for some anomalies to determine where it ends (a string of zeros, a header for another file type, some human readable text etc). In case they don't contain the header I'm afraid they are lost forever.

Also comparing a messed version to the original (let's say something you can download again from the internet) would be VERY useful.