first of all, never open attachments before you are sure they are not infected.
If you are not using a prog. that delete them the very moment you download your email, then you have to save them to the disk and run an antivirus .
If you are using outlook express, disable the preview window : go to tools > options > Read , uncheck 'Automatically download message when.....", this way you'll avoid to download malicious Activex on your Pc. (web pages might have it in their code)
If you still want to see the preview, simply hit your space bar when the message 's highlighted/selected.
Get rid of Explorer, and install Mozilla Firefox (Explorer is very easy to hack).
Install and Run Ad-Aware 6.0 by Lavasoft (it will detectand delete all those nasty spyware progs you pick up during your surfing)
people don't realize that even surfing the web can be pretty dangerous .
I've been hit by a virus-dialer, I knew that dial-up connections were a target for this kind of virus, but this one uses Broadband to connect to a number somewhere and it costs you several $ a minute.
YES I said it uses broadband, it seems impossible ,but this is what happens.
It was an activex downloaded from a web site!!!!