can't create new user accounts


Well, I have been trying to create a new user account. I have one
administrative profile and one user or guest - so 2 in all. So i decided
to try and make another one adminsitrative profile to see if I could use
INternet Explorer because for some reason I can't on the admin but only
on the user/guest ( but was told to send back the pc to HP to fix).
Anyways I tried to make it but it said something like" you can;t make
this beacause you have one or more of the following symbols :
/\":;|<>+=,?* " but i didn't even put one of those in i just put my
name - miles
So I asked around and was refered to this site, so does anyone know
what to do? and if so please do keep in mind that I dont really know
anything about computer and such, Thank you.