If you think your laptop is infected by a virus, what you do next depends on whether you already have antivirus software installed.
First of all, you should already be running a current antivirus program on your laptop, such as Norton AntiVirus, McAfee VirusScan, and PC-cillin. Any of these should detect a virus when it arrives on your laptop, and they should warn you if your laptop starts to act suspiciously: changing system tracks, altering file indexes, and mass e-mailing recipients from your address book.
If you receive a message warning you of this sort of activity, stop whatever you're doing. Shut down any programs that are running, including your Web browser and e-mail. Physically disconnect the cable to your broadband Internet router or shut off your wireless router. Then follow the instructions of your antivirus program to quarantine or remove the virus. After the virus has been isolated, you should run a full antivirus scan in search of any other viruses or malware.
What do you do if you suspect a virus and for some reason you do not have an antivirus program running on your laptop? Immediately shut down your machine and disconnect it from the Internet. Then head to a computer store and purchase the best antivirus software you can find.
Most antivirus makers instruct users not to install their programs (and allow the existing virus to do more damage) but instead that you boot the laptop from the antivirus software CD and scan the system from that disc. You may have to change your system BIOS setup options so the CD drive is the first place the system searches for bootup tracks. Once the antivirus program has cleaned up your disk, you can install it on the hard drive and enable automatic, regular updates.