The first thing to do is not to panic.
A virus requires access to a computer in order for it to be able to replicate and spread, and the first line of defense against viruses is having good defenses including an antivirus app like Norton. That said, make sure your computer is running as fast as possible by determined what applications are slowing it down (can you do that? You might need help from an expert). And finally, back up all your important files such as family photographs and business must-haves!
If you’re reading this Q&A then there’s some chance that something has gone wrong on your laptop or desktop! Maybe you suspect a virus or maybe there’s just been some kind of software glitch.