How to get rid of virus on your network

1. Patch your systems according to the latest instructions from Microsoft.
2. Read on a daily basis on few AV vendors web sites for the current threads, virus, worms.
3. Notify your users when you see that an email worm is spreading out fast.
4. You do not need to do the number 3 if you use AV for Internet or AV for mail and Content and Spam filtering.Your gateway products should be informed before you even realize than a new thread already exist. Therefore as long as you got right tools properly installed on the gateway nothing malicious will pass through your network.
5. Get centralized application of an AV product.
6. Update your systems immediately, as soon as your vendor released new virus definition databases. Centralized applications of AV do that in few clicks..or without user intervention.
7. Get always informed from your AV Vendor for product patches, new releases.
8. Be patient you will be not the first neither the last that will got a network infectec by virus.
9. Be prepared to loose 10% of PC's if you put AV product for the first time, so a ghost of a prototype PC if you have the same brand of PC's on your company would be a good idea.
10. Test your systems if they are really work using the famous eicar file. This just to see that your engines are running properly. Go, first read then implement from the link: http://www.eicar.org/anti_virus_test_file.htm
11. Good Luck