Given that you were able to log in with your user account, that is obviously not banned.
Which means your desktop probably has an IP address that got caught in some other users ban.
Send me a PM directly with the exact message that is displayed to you when you attempt to sign in from your computer. Include in that PM (if it's not already in the message) the external IP address that you have on your computer (Use Google and search for "What's my IP address" for a link to anything that will give you that if you don't already know it) and I'll sort it out for you.