If your computer is convinced it does not have a virus, when, in fact, it does, there can be problems. Especially when the reason it does not think it has a virus is because of a virus. What kind of virus could do this? Boot sector virus. Considered evil and difficult, boot sector virus's lodge in your boot sector (the part which "boots" your computer), and as soon as you turn your computer on, the virus has already loaded itself into the memory.

You can take precautions to try to prevent boot sector virus. The best way to do this is to switch your operating system from Microsoft Windows, if that is what you're currently using. Windows is one of the only systems, which are commonly infected by viruses. This may be due to faulty programming doings. An example of faulty programs, is demonstrated when you have an e-mail with an attachment, and it is automatically opened, and the instructions of the attachment are followed, regardless of what they say. That is a significant way viruses are put in computers.

If you are using Microsoft Windows, you may want to consider switching to either macs or linux machines, as they are rarely infected. They both contain built-in safeguard to protect your computer from the above-stated problem, which will help keep your computer virus-free.

If you did not prevent the virus, and have it, removing the virus can be quite tricky, but the best way to go about it, is to make a back up disk. The reasoning is that if your boot sector is contaminated by the virus, and your computer is loading off the boot sector, it is loading off the virus. If, however, you put your clean, virus-free disk in the drive, your computer loads from that, instead.

Along with boot sector virus removal, your computer might need a few other protection precautions, such as spyware and adware protection.

Spyware is far less harmful than viruses, but similar. It does much of what the name implies: spies. Web cites with spam, they can plant a program to your web browser, which will track which websites you visit and what you buy and such, and send that information back to them, so that they can use it to market things to you. In effect, you will receive more pop-up windows and slow down your computer.

Similar to spyware, adware can divert your web browser, which will send you to web sites you didn't intend on visiting. It, in turn, will prevent you from reaching the site you did intend to visit.

There are several adware and spyware removal programs to help keep your computer safe. Install these programs to your computer, and you will find you computer running faster, less pop-ups, and more control over what is going on in cyber space.