Could you post a screen shot of your My Pictures > Lightroom folder so that I can see what Catalog files have been created by Lightroom. See the screen shot of my folder containing my catalogs. You can see the path at the top of the screen shot, that is the default location on my Win 7 64 os. I do not know what is your operating system.
I just need to get some more info so I can let you know how to proceed.