One day you notice your Windows-based computer is running more slowly than normal. You decide to restart it and see if that fixes the issue. Windows loads and a security alert pops up to notify you that you have a virus.
The first step is determining that you have a virus. If you do not have a Windows computer, you are likely not at risk of having a virus. For years, Macintosh computers have been virtually immune because virus writers did not target those systems. This is beginning to change, but for the most part only Windows machines are susceptible to infection. Online virus removal is a one of the best technique for 100% surety of virus removal.
A computer with a virus on it will generally run much slower than it normally does. This will happen suddenly. There are many different ways a virus can appear on your machine and many ways it can manifest it, but if your PC is running slower than is normal, you should get it checked out.
Sometimes, however, the virus changes your internet settings and prevents you from finding resources online. One way around this is by using the Safe Mode tool that comes with all modern versions of Windows(see also:How to Run Virus Scan in Safe Mode). To access safe mode, restart your computer. Begin to tap the F8 key before you see the Windows loading screen. If you've pressed the F8 key at the proper time, you will be presented with the Safe Mode menu. Select 'Safe Mode with Networking.' When Windows loads, you will see the words 'Safe Mode' at each corner of your screen.
Note:Your system need strong antivirus software,choose best anti-virus for your system.
Sometimes, however, in spite of your best efforts you simply can't remove a virus on your own. When that happens, don't be afraid to take your system to a professional (http://www.vtechsquad.com). They have the knowledge to remove any threats and can get your system back in working condition.