There are several signs that your computer may be infected with a virus.
Some common symptoms include:
Slow performance: If your computer is running slowly or freezing, it could be a sign that a virus is using up resources.
Pop-up ads: If you're seeing lots of pop-up ads or your browser homepage has changed without your permission, it's possible that you have a virus.
Crashes: If your computer is crashing frequently or displaying error messages, it could be due to a virus.
Unusual network activity: If your computer is sending or receiving a lot of data when you're not using it, it could be a sign that a virus is communicating with a remote server.
New programs: If you see new programs or files on your computer that you didn't install, it's possible that a virus has placed them there.
Antivirus software disabled: If you are unable to launch Antivirus software, or it is reporting itself as disabled, it is possible that a malware has disabled the antivirus software.
If you suspect that your computer is infected with a virus, it's a good idea to scan it with an antivirus program. Keep your antivirus software updated to protect against the latest threats.
You can try running a malware scanner like Malwarebytes which usually is effective in catching most malware, adware, and viruses. Also, you can run a full scan using the antivirus software that you have installed on your computer.
Please note that viruses can be highly sophisticated and can evade detection even by the best antivirus software, so if you're still experiencing symptoms after running a scan, it may be a good idea to seek additional help from a professional.