If your computer is working fine sometime before and then show sudden glitch, sputter, slow down or crash, then there may be some virus infection there in the system.
This intrusive agent may hiccup your system and this is the reason that in most of the cases rebooting the system works for you. Here are the five signs that give you the signal that there may be some kind of infections in your system:
If your computer is infected, the entire space of your computer screen will be running into a pop-up ad while you're accessing the Internet. Although most of the browsers provide protection against these annoying pop-ups, but sometimes you can’t ignore them completely. There may be a reason that you see these ads on one or more sites because your browser is badly-configured. But if you see the pop-up messages even though your browser is not open, then there is a virus attack on your system.
So to get rid of these pop-up ads, first you need to run a scan with anti-spyware software because it digs deep into your settings to identify spyware which has left behind.
Unable to open programs and tools
When your computer starts misbehaving, often people rely on one simple command: Ctrl + Alt + Del. This "three-finger salute" opens up Task Manager and here you find a lot of information about your PC. But the problem becomes worse when "three-finger salute" doesn’t work and you’re unable to open Task Manager. Moreover, you might receive a random error message. This is very strong signal that a virus is messing with your PC and stopping Task Manager to get opened. And in this way you remain unknown that it's eating your system resources and causing various other issues.
Any virus or such infection is so smartly written software that they might block number of programs or utilities to hide themselves and they can be only found by deep-cleaning anti-malware software.
You’re locked out of your system and can’t access necessary programs
How will you feel if you're accessing the Internet and surfing something important and suddenly you receive a scary message that says that you're locked out of your computer? This may be sent from law enforcement or an anonymous blackmailer. This happens because a virus is blocking some important programs from running, or may be encrypting your files so that you can't access them. In this way these illicit programs trap the computer users and demand to pay some money in order to give the controls of your PC back to you.
So you really need to be very careful from them and need to be prepared in advance.
Your computer is the source to spread annoying messages
This is the nature of the viruses that they spread from one machine to another. If your friends and contacts of emails are complaining that they are receiving some annoying messages from your email address, it means your system is infected. The virus infection might try for sending out spam through your email account and the receiver may receive these messages anywhere. Plus, it could take control of your other social media accounts and often they attach themselves as a link or attachment to the virus anywhere in the mail or post.
So it’s advised to keep an eye on your social network posts and on your email's "sent" folder. If you notice that you haven’t sent those mails which are reflecting in your sent items, it's likely that you have a virus infection.
You can’t notice the annoying changes
Viruses are powerful programs which can hide deep in your computer without letting you their presence or raising any red flags. They'll just do their intended task without making noticeable changes into your system initially. As you can’t notice them initially or they don’t show symptoms initially, it doesn’t mean that you can take them lightly. They are very dangerous entities and could snag your sensitive information like banking details, passwords, etc. Plus, they may use your computer to spread themselves from one computer to another.