I was asked not long ago for advice on ridding a computer of a virus that infected a friend's computer. She had begun to notice all the usual telltales: slow bootup, pop-ups continually interrupting the browser, being redirected to strange websites. I pointed her to some virus removal tools and advised her to put a good virus checker on the machine. I also gave her one other piece of advice that I bet most of you reading this aren't heeding:
Don't browse the internet as an administrator!
Normally, when you set up a computer after purchase, the account you log into has what are called "administrator privileges". These are rights necessary for installing new software, creating new users, restricting access to files, etc. People tend to use the out-of-the-box account because, hey, it's already there.
When a virus invades your computer, it attempts to copy itself to the machine and register itself with the operating system as just another program. "I come in peace," it says. It can also attempt to do other things, like open a communication port, install a keylogger, set up a web proxy, or all kinds of other things you won't like.
Normally, many of these steps require adminstrator privileges. Since the virus is piggybacking on the user information of whomever is accessing the email or web page that hosts it, a simple way to protect yourself is to browse as a user without administrator privilege.
This is simple to set up:
Instructions for setting up a user in Windows XP
Instructions for setting up a user in Windows Vista (select My computer is in a workgroup)
Instructions for setting up a user in Windows 7 (select My computer is in a workgroup)
Note: during the setup, you'll have the option to define the type of account. For example, In Windows XP you'll see a choice between "Administrator" and "Limited". Choose "Limited".)
In the future, use the Web User account when logging onto the machine. If you need to perform some administrator task, like installing new software, you will need to change over to the adminstator account. This seems like a chore, and it can be at times. But you can save yourself a lot of headaches down the road.
Of course, you will also want to install some good virus protection if you haven't already. I recommend Avast! or AVG. Both of these are free downloads and work better than the for-pay products that get preloaded on most new machines, like McAfee or Norton.
If you think you've already got spyware or a virus, I suggest downloading and running the following (run them all; no virus scrubber gets everything):
All of these have free versions that work well.