3 different program files?

I was trying to free up space on my PC and noticed that there are 3 different places where my doents are saved. Should I keep the regular My Doents on My Computer and delete the others? The other 2 are located in C drive, Doents and Settings, then my name. The other is in the C drive. I don't know if they are just copies of the same thing, or are they needed for my PC to run? If this doesn't make sense, I will try to rephrase it but please help. Thanks