Also, try changing the password of your email account.
Make sure that Windows is fully patched by visiting Windows Update website or opening Windows Update program in Vista or Windows 7.
Scan the computer using MBAM, to check if there's malware that your antivirus failed to detect:
I have a Toshiba laptop and my broadband server is AOL. For the past week or so e-mails have been sent from my e-mail address to everyone in my address book but I have not sent them and I have not been on line at the time they were sent.I have been recieving a lot of angry replies back as the mails are all for links to a site selling Viagra.
How can I stop this as I'm going to be losing all my contacts if it goes on any longer. HELP!!!!!!