Problem with user profiles

Hello,

I have a strange problem with my account of windows vista.
There is only one account created (usuario1 which has administrator
privilegies).
However, each time I login into the system it seems that there are several
profiles for that user, since each time I login into the system the desktop
is different and some programs don`t work properly. I haven't created any
profile so I don`t know what is happening. I have taken a look to the
registry , and there are many entries into the HKEY_USERS but I am not able
to delete them.

Could someone help me?

thanks a lot in advance.