Hi
Personally I don't let it just default and save my photos where ever it wants to.
I created a folder, D:\Photography. (I have two internal hard drives, hence D).
Under this I place sub folders for each category, i.e. Dog Pictures, People, Vintage Cars, Race Photos etc.
It makes it a lot easier to keep track of where things are and what you have.
If you want to take the time to reorganize your images you will find out what you have duplicates for.
Then I recommend that you back them all up either to a external hard drive or DVDs.
Having them on only one drive is asking for trouble, sooner or later something is going to go wrong and you will lose data.
Mike