Would you settle for secure enough? Echo. Until you or anyone else can demonstrate that they can hack my computer I am not going to worry about my computers security.
On the other hand, it has been demonstrated countless times that you window's users can be very easily hacked. If you doubt me I can send you an e-mail that will make my point, all you have to do is be running XP and open the attachment with Outlook :^) Or if you prefer I could direct you to a couple of websites that will do more subtle things to your computer.
If you send me an email I will open any attachment. Do you want to see who crashes who first? This could be fun.