Nowadays there is lots of decent free virus removal software for windows based computer that can do great job protecting PC from infection of malicious threats. You do no have to pay for antivirus software if you use it for personal or home purpose. Business user need to purchase the license to use virus removal tool. With lots of choice of freeware antivirus, lets take a look on the functions of virus removal software:  Protecting your PC from virus malicious infection all the time. Scanning function to detect dangerous threats that might exist within the PC system such as spy wares, worms, Trojans, viruses and ad wares that can cause fatal damage to your computer.  If the software detect the threats, it removes them or if cannot, the threats will be quarantined in order to keep the computer to run smoothly with less errors. Automatically updating it for new threat definitions from the vendor web site. However user can turn this function off in the antivirus software interface. Some of antivirus can do Internet link scanning to check if it safe enough for you to click and enter a particular site Email scanning function to detect any email and its attachment for viruses. This function is automatically done and can be turned off. Some free virus removal software can scan for downloaded, saved or copied file for any dangerous threats.