Jesse,
This won't help for the pics you already lost - they're gone, unless you did
not yet erase them from the card or camera memory. But to prevent this in the
future, check your camera's settings; you should be able to access them from
a Menu button on the back.
Many cameras have a setting which allows you to NOT reset the numbering each
time you clear the camera or storage card memory. For example, if your
particular camera uses, say, Image001, Image002, etc., when you download the
pics to your PC and reinsert the card, if you erase the card (or camera
memory, if you're not using a card), the camera usually defaults to start
numbering over again, with Image001, Image002, etc. There's no conflict in
the camera, because the pics you had before with those numbers no longer
exist - as far as your camera "knows". But of course they DO exist on your
PC! If you have a setting to not start numbering over again, the camera will
start numbering right where it left off before. If the previous batch was
Image001 through Image100, the camera will "rememberthis for the next batch
and will start numbering the new batch as: Image101, Image102, etc.
Eventually, of course, you will have to reset to Image001, but by then you
will have prepared for this.
You may also want to set your software, either the camera software or
Windows Picture and Camera Wizard, to automatically create a new date with
the date as the folder name to download to. But remember, if you download
more than once on the same day, you could still run into the overwrite
situation!