confusion about my attempt at empire account

[WriterBoy]

Ok, the other day I started a thread about trying to start an Empire account on my computer. I already have a Party account on this computer. The people who replied assured me that I could still set up an account on Empire on this same pc but I tried this morning and it denied me, saying it detected my party account.
So I must have done something wrong, but what is it? And, does that mean it's now too late?