By Kim Komando
Gannett News Service

Q. In the computer world, the terms virus, worm and Trojan horse are thrown around casually. Are they the same?

A: A virus is a program with damage ranging from irritating messages to hard drive destruction. A worm spreads through e-mail. It finds e-mail addresses on a hard drive and sends copies of itself to each. A Trojan horse is a program that may download malicious programs. You can avoid and eliminate these by installing an anti-virus program.

Q. My Windows ME computer was upgraded to Windows XP. Can I go back to ME?

A: Yes, if the old system's files were saved during installation. To check, click Start, Control Panel, and double-click Add or Remove Programs. In the list of programs, click Uninstall Windows XP. Click Remove. If Uninstall Windows is not present, the files were not saved. You will need to reformat the hard drive and reinstall ME.

Q. How do I prevent Google from indexing my online journal?

A: Prevent search engines from indexing your Web site with the Robots Exclusion Protocol (www.robotstxt.org/wc/norobots.html). Once the "robots.txt" file is completed, upload it to the root directory on your server. The next time Google's robot searches your site, it will follow your instructions. If you want your indexed information removed immediately, you must make a request at Google (http://services.google.com:8882/urlconsole/controller).