Windows computers are often subject to virus and other malware infections, but not all slow or misbehaving PCs don't necessarily have malware. Here's how to check if your computer has actually been infected with a virus or malware and if it's dangerous or not.
What are the signs of a virus?
Poor performance, application crashes and computer freezes can sometimes be a sign of a virus or other type of malware causing anomalies in normal system processes. However, this is not always the case: there are many other causes that can slow down your PC, such as a clogged registry or a defragmented disk, try to check the condition of your computer with our suggestions.
Strange applications that start automatically on your system may indicate malware, but, again, you are not told that this is the case. Sometimes it can happen that some applications open a command prompt window when they update, strange windows displayed on the screen could be legitimate processes of a software or of the system itself.
Likewise, just because your PC works properly doesn't mean it doesn't have malware.
Compared to viruses a few years ago, modern malware often does silently hide in the background, trying to circumvent the detection so that we can acquire sensitive data such as your credit card numbers and other personal information. In other words, modern malware is often created by attackers just to make money and consequently if well designed it will not cause any obvious PC problems.
Sometimes malware causes PC problems, sometimes they are invisibly active while sneakily reaching their goal in the background. The only way to know for sure if you have malware is to scan the system.
How to check if an active process is a virus
To check the active system processes just open the Windows Task Manager pressing Ctrl + Shift + Esc or by right-clicking on the Windows taskbar and selecting "Task Manager".
The panel that opens in addition to normal applications such as Google Chrome, skype and others shows in the background processes part many processes that have strange and confused names. It's normal. Windows includes some background processes, but also the PC manufacturer and installed applications often add some.
Poorly designed malware usually uses a large amount of CPU, memory or disk resources and this could already be an indication of an unusual presence. To find out if the program is malicious, right-click on Task Manager and select "Search online" to find more information.
If anything positive is indicated during the search, it is likely that it is malware. On the other hand, it should not be taken for granted that your computer is virus-free only because the task manager does not indicate anomalies and all processes seem regular. A malware could disguise itself as software like "Google Chrome" or "chrome.exe", if you notice that it is located in a different folder on your system, we recommend that you run an anti-malware scan.
The online search option is not available on Windows 7, if you use it you will have to search for the process name on Google or another search engine.
How to scan your computer for viruses
By default, Windows 10 always scans your PC for malware with the integrated security application Windows Defender, but you can launch it at any time.
On Windows 10, open the Start menu, type "Security" and click the "Windows Security" link to open it. You can also go to Settings> Update & Security> Windows Security> Open Windows Security.
To run one anti-malware scan, click "Virus and Threat Protection".
Click "Quick scan" to scan your system for malware. Windows Security will scan and give you the results. If malware is detected, it will offer you to remove it automatically from your PC.
If Windows Defender doesn't find anything and you want a second opinion, you could run a scan with another security application.
I usually recommend Malwarebytes, which works well with the Windows security system and provides an additional layer of protection for your PC. The free version of Malwarebytes allows you to perform manual scans to check for viruses and other malware on your computer. The paid version adds real-time protection, but if you're just checking for malware or ransomware, the free version will work perfectly.
Windows 7 does not include integrated antivirus software. For free antivirus, you can download Microsoft Security Essentials and run a scan. Provides protection similar to Windows Defender built into Windows 10.
If the antivirus application detects malware but cannot remove it, try running a scan in safe mode. You can also make sure you don't have malware on your PC restoring Windows 10 to its default state.