[mariatamis]

1.Your system slows to a crawl for no apparent reason.
2. The machine crashes, with or without an automatic restart.
3. Error messages pop up repeatedly.
4. Programs or files open slowly or not at all (especially security apps).
5.. You can't access drives or other storage media.
6. Certain Web sites won't open in your browser, especially those of security software vendors.
7. You can't download updates for your antivirus software.
8. You can't print.
9. A program disappears from your system.
10. Strange icons are added to your desktop, or programs appear that you never installed.
11. The unused space on your hard drive disappears (which could mean a worm is making copies of itself).
12.People in your contacts list receive e-mail from your account, often with a virus attached.
13.There's a big jump in the amount of traffic on your network, especially outbound.