Login Fail

I chose a hosting provider Just Host from your website today to make the installation of WordPress on my website easier. I have followed all the steps correctly, but when I try to login I get:

ERROR: Invalid username.

I have tested the database that was automatically set up, created a new user for the database just incase the default user password wasn’t correct, removed the WP E-Commerce plugin that I installed via FTP in the Plugins folder as your instructions suggest that it may be interfering website and cleared the browser cache and history…

and I still can’t login.

I can supply my FTP if needed.

thanks!