COMBINATION RETROVIRUS + ??

I think I got this across yahoo messenger, but don't know for sure.  Computer started sending SPAM E-mails to everyone in my address book, and redirecting my web browser to phishing sites wanting to give my bank account info to them so they could pay me the several trillion dollars I had just won.  I rebooted and ran a full system scan and found nothing.  I then did a system restore to about a week ago.  As the system rebooted I watched Norton being turned off and disabled.  I turned it all back on and did an update.  64 MB download (the entire virus definition file?)  I ran another full system scan, still nothing found.  The problem persists.  I'm stationed somewhere that I cannot take this device to someone very easily, so this will have to be catch as catch can assistance.  Thank you.