(Operating system Win7)
Find out the name of the software and then google it. I have already eliminated something that annoyed me. And if the antivir program have, that certainly helps. But not all virus messages are clean. Some even want to convince you that you are buying antivirus software quickly. Before buying, I had weekly warnings, after buying once a year.
Who says that you have a "malicious software" on your PC? (So a software, virus scanner, Windows or what)
Windows 7 has usually integrated the Defender, which should warn of viruses or something like scanning, and also eliminating. But only with regular updates and scans of hard disks.
If this message is displayed on a web page, it is just a list and clicking on it loads even more a "malicious software" down.
How do you come up with this idea? This would have to do your virus scanner itself.
Otherwise, let the https://de.malwarebytes.com/...dwcleaner/ run.
does not require installation.