There are several free computer protection software programs available for online download that are often better than commercial applications. The Avira antivirus program, for example, has better reviews than many commercial products. Avira will not hurt performance like McAfee and Norton and is very efficient when scanning for viruses. Also Avast is another excellent antivirus software program that runs efficiently without hurting performance. AVG free basic is still a very good antivirus product that I have used for years, but Avira and Avast have better reviews and I have recently switched to Avira.
I now do a complete restore using imaging software if I ever become virus infected or my computer begins to slows or become unstable. There are too many down-loaders and key-loggers that can be installed on your computer once you are infected by a virus. Many of these down-loaders and key-loggers are not detected as threats so you can continue to have virus problems and loss of personal information even though you have cleaned the viruses from your computer. It is best to reformat and reinstall Windows. This can take considerable time without imaging software. I run a computer lab of 35 computers and my students have administrator rights to be able to complete their labs. After 6 classes each day the computers can get very corrupted and unstable which requires some maintenance to keep them running properly. I use to spend some considerable amount of time each day restoring a few computers. However, using imaging software I spend about 15 minutes doing a complete restore of all 35 computers at the same time. Now I can concentrate on lessons and curriculum and not worry about the computers. This is sometime every computer lab teacher needs to free up his time and keep all the computers running at their optimum.
Part Image is a free open source product that works very well. It is a clone of Norton Ghost. I prefer Norton Ghost because I can run it from DOS either from a flash drive, CD, or on the hard drive. DOS is quick to boot and easy to use. Some of my students ask me why we need to learn DOS or Linux and I say to them, “Windows is the problem and DOS (or Linux) can be a very good solution”.