Unnecessary User takes up space

Please help... the previous suggestion does not work. See
response to first reply.
thanks!
>-----Original Message-----
>It appears when I originally set-up my computer it link a
>user name with the serial number. There is a second user
>tied to the OS and it is killing performance as sharing
is
>an issue. Cannot find how to fix this problem. DO I have
>to rebuild? Any advice would be greatly appreciated. (I
>have XP home)
>.
>