Your computer has been acting up a lot lately. It keeps crashing, it's slow and, to top it off, you keep getting pop-ups you don't want to see. If you are experiencing these issues then your computer may have a virus.So is there a way to prevent things like this from happening again? While there are various antivirus solutions you can take, it's best to know how malware affects your computer first so you can quickly recognize and deal with the problem. Here are a few ways to find out if your computer has a virus before it's too late.