Vista - Multiple folders and files for one user

I am using Windows Vista Home Premium on a new laptop. I am the only user
on my computer. However, I seem to have multiple and different files and
folders. For example, depending on the method I use to go on the internet
there are different favorites. I also had different versions of Windows Mail
which contained different files. I also can't log off the internet (dialup)
because "it is not possible to disconnect at this time. The connection is
currently busy with a connect or disconnect operation" (I have to pull out
the phone line or log off through Windows Mail which mostly asks if I want to
disconnect when I close it ).
Different programs also seem to be linked differently or stored in different
places and some programs that are on the computer can't be found in the
uninstal program.
When I look in User Accounts there is only Di (Administrator) but in Folders
I find Di under desktop but also under Computer - VistaOS(C there is both
Di and Di.Di-laptop. Each has a set of Documents, Pictures, Favorites etc
etc.
I did try to connect to my old computer and probably used Di laptop as a
name for this computer but it didn't work anyway.
I have tried moving files around but don't seem to have done much good.
I hope I have explained this OK (it's a bit complicated and hard to
explain). I hope someone can help sort me out. Thankyou.