Beth is correct AVG is great! I have used it for a couple years. Use it in conjunction with Spybot and Adawars(for syware) and your good to go.
That said I don't think the e-mail really has anything to do with a virius. It could but highly unlikely. 2 things could have occured.
1) spyware...the more likely cuprit and a virius check will not find it so get a spyware remover like the 2 i mentioned)
2) sometimes "bad people" simply send out phishing e-mails...they are random and try to get people to enter personal info by looking like they are legit.
hope this helps.