Barbara Shaw
I have had a few e-mails with attachments of the type readme.xls.lnk and bestupid.doc.lnk which if you have extensions switched off will not look like executables but are (shortcuts). Even if they don't hide the second extension (the one that instructs Windows) in the e-mail it may be of a length that wraps the second extension so you read the first line as DOH.txt .
I have been extremely lucky but then I never open any attachment without waiting and thinking do I trust this, even from known sources I often wait a day to see if there are any more that look the same.

having said that I just had a hardware crash (second this year) this time the sound card was totalled. I bought Norton at the same time - I am overdue for viralling out of control.
As Bob Noyce (Intel) said - only the paranoid survive.