Windows login different in My Documents.

[Skyrider]

At my dads computer, for some reason my login usernames when you login in to windows is totally different than the usernames in my documents. Does anyone knows a way to solve this? As my username and my dads username are swapped / mixed up, this is very confusing.

 

[Enigma]

In what way are the mixed up IE Skyrider = DAD and DAD = Skyrider?