MY MAPS HAVE MYSTERIOUSLY DISAPPEARED?

So I seem to be having some trouble with my maps. I recently moved and had copied my rpgmaker2003 game project onto my external hard drive to put on my old computer which already had rpgmaker 2003 installed on it. When I unzipped it to my computer and opened it in rm2k3, I noticed that not only were a handful of my maps missing but my maps were also jumbled up with incorrect titles (for example, "house interiors" had a map of the city, and the city map had the house interiors mapping instead). Not all of them were like that but some were. I couldn't figure out why. So I unistalled and reinstalled rm2k3 and tried to open it again -- same thing.

I called the person who had my original project on their computer and asked them to do me a favor and look to see how many numbers of maps was in the folder. It turns out that it matches the number I have currently on my own folder, which doesn't make any sense whatsoever. I know for certain that I saved my maps to my project since I had been working on several different ones for weeks at a time. Not only that, but some of the maps I had created in the beginning of my project are gone now too, including two critical introductory maps.

I really am at loss as to what to do here. I don't know if this is uncommon or not or if this is suppose to happen or if there's anyway I can atleast prevent it from happening again... It's like a bunch of random maps just disappeared out of thin air. Was it because I moved it to my external? I really don't know what to do.

author=LockeZ
It's possible that this happened because of bad file copying, or possibly because you opened two copies of RPG Maker at the same time (which can cause big problems).

Crap. Well, I figured the latter was the cause. But I just called my friend who has the original copy and told him to open it and see if its the same as it is on mine -- and it is. And that is the original, not the copy of it. So even the original got messed up... can that happen by bad copying? And how can I prevent it from happening again? I really wouldn't want to lose any more of my stuff.