In order to get rid of viruses you first have to know if you have any malicious files on your computer. If you suspect you have an infection then you should first run an anti-virus scan to see if you indeed are infected with viruses. There are plenty of anti-virus programs you can use to perform a scan. A free one I can recommend is Avast Anti-Virus. It’s a great anti-virus for home users.
Some common symptoms of virus infections are:
– Computer operations slowing down (sluggish performance)
– Lots of pop-ups
– Files become missing
– Messages saying drive is full and you know it shouldn’t be
– Strange activity such as programs opening by itself or closing by itself, or computer shutting down by itself.
When running a virus scan be sure to physically disconnect from the internet (unplug the network cable, or turn of your wireless). After running a full system scan for viruses, the anti-virus program should be able to fix any problems or infections it found. If it can’t then make a note of the files that are infected and quarantine them so the infection doesn’t spread. If the virus software cannot fix the infections it found, it’s not a bad idea to try another vendor’s virus scan just to see if it can fix the infections. It is not recommended to just go find the infected file and delete it UNLESS you know for sure that the infected file is not needed for system operation.
Most good virus programs can fix most infections, but if you have a bad infection and substantial file and data damage then you may just want to take the ultimate step and just re-format you hard disk which will erase the entire drive and prepare it for fresh operating system install. If you opt to do this then make sure you have your Windows installation disk handy, and be sure to back up everything you would like to save because formatting the disk will erase EVERYTHING.
Performing a format and OS re-install is very easy. Just boot from the installation disk and follow the prompts. The installation actually allows you to format the drive before installing the OS.
If your infections lie on the hard disk then formatting the disk will definitely get rid of them. Some viruses are designed to alter the CMOS RAM, but this is not usual, a format of the hard disk should do the trick 98.9% of the time. Be sure to follow the advise in the Virus Prevention (link below) article to keep from being infected again.