I have a BT Voyager 210 router which I installed from new last week. The first thing I did was to change the admin password. I have used this for a week with my new broadband connection.

This week I went to access the advanced options (which requires you to enter your name and password) and found that under the user name dropdowns were two email addresses which I had never used as a user name - in fact they belong to a relative (young, intelligent and IT literate) who about a year ago used my computer while visiting. These email addresses are on my outlook address book and I recently also emailed the owner of the email addresses to tell of my new email address, domain, and ISP.

The router has a firewall, I have a software firewall and virus checker and adware spyware utility (Bullguard) installed on the computer.

My question is how did the email addresses appear in the router? Is someone attempting to hijack the router? Is it my relative? Why even after resetting the modem (phyically and through the modem software) do the rogue user names appear? How do I know that my PC and internet have not been compromised?

I've never heard of this happening before and, if you've correctly performed a hard reset on the router where you've returned all of the router settings back to the factory defaults, then there's no logical way that the router would be able to remember those settings. Therefore, I'm thinking that it's probably Internet Explorer's 'AutoComplete' option - this function is used to remember your usernames etc on web sites that you visit. If you are configuring your router through a browser (which is the normal way to do it), then you are viewing a local web page so Internet Explorer may be trying to help you by showing you usernames that it has remembered. A similar function is provided by the Google Toolbar and others.

If you aren't sure that this is the problem, then I'd recommend changing your router password to something else and also change your wireless network encryption key, if it is a wireless router. Always use WPA or WPA2 (rather than WEP) encryption wherever possible as this updates dynamically, making it much harder to crack.

Hope that helps

Thanks for your help but the mystery still remains - though your suggestions make perfect sense to me and I hadn't thought of the autocomplete function.

I have removed all the autocompletes, and done another reset of the router and the names keep popping up.

I can see no reason why the two email addresses of the same individual should appear in this box other than a malicious one and I don't know how you would do it if you wanted to. Is it possible? I think I need to challenge the person concerned.

Any more thoughts?

Well, if this relative of yours is IT literate and inteligent, I find it hard to believe that he will be that stupid to leave traces behind that you can so easily detect. To make sure, as it was suggested above, I would put everything back to factory default and start all over again. This time, I would pay extereme close attention to what I am doing when I am changing factory default setting to what I want it to be. I would look to see what options are automatically filled in and are given to me, before I click "ok" or choose "next".