Another very important thing to do, if you have the facilities, is to make it a habit to 'trace' the addresses of any people who do try to launch or install viruses or so-called Trojans...
After doing a proper trace you will be presented with a lot of information on the individual and/or organisation making the 'attempt'... Normally included in such information is not only the IP used for the specific 'attempt', but also the range of IPs used by said person or organisation...
Using this 'range' of IPs info, enter the complete 'range' of IPs into your A-V software so as to 'block' them.
If you do this routinely with every 'attempt' you will fairly quickly notice that the frequency of 'reported attempts' is reduced, more and more over time. Users must play an active role in protecting themselves - Do NOT depend only on 'automatic' processes !

If your A-V software does not allow you to do this than it is inadequate software and you should replace it with something suitable to purpose. (Good A-V programs also include 'tracer' functions.)

There are very many completely nonsensical things both said and believed about Anti-Virus programs...
There are not very many that actually do the job required...
Be cautious.

The 'good' ones do not simply clean and 'repair' problems...
They STOP problems from ever entering your machine.

Also, have a look in the 'sticky' thread here about Alternative Connection Ports...
You will find commonly used ports for Trojans...
You should be able to block any and all traffic attempting to use those ports.

Last, if you DO become infected, please also try the link in my 'sig' for Virus Removal Tools...
They are free.

__________________
Fusion for REAL!--CDex 1.51--Wackyuses--Bitzi - Check Files Before Download !--.mp3 File Name Change Problems? Try Rename-It!--Alternate PORTS--Avast- Anti-Virus--WindowWasher--IrfanView--PC Pitstop - Test your PC !--Mac OSX Troubleshooting--GO .ape ! - For 'Lossless' Audio Compression--Port :6346 - Test If It Is 'Blocked'--Cole2k Codecs--OldVersion - Newer isn't always better !
Nod32 - Free Virus Scan: Use ESET's Online Antivirus Scanner

Tomorrow's forecast:
Sunni in places, Shi'ite in others...