RE: How Secure is Windows, Really?

Wikipedia has a decent definition:
http://en.wikipedia.org/wiki/Computer_virus .  Besides virus, it
mentions worms, Trojans, logic bombs, and other malware. 

Recently, a lot of malware contains blended threats - viruses containing
worms or adware that installs a Trojan.  As such I've started moving
away from saying virus, Trojan, and worm and simply say 'malware' to
describe the overall category.  'Badware' to non-techies.

And of course hardware isn't immune.  The Sony blended threat combined a
rootkit with an exploding battery.  :)