The fake Windows Registration Checker is one of the numerous scams, created by cyber criminals in an attempt to gain profit by unsuspecting users. The scheme is craftily designed, since its bogus screen looks legitimate, but the plot of the con is extremely shallow.
What this scam actually consists of is a Windows Registration Checker window pop-up, which comes out of nowhere and requires all your personal and credit card details to be filled in. Though it is highly probable that such a pop-up may shock you, do not let it trick you with its cunning text "Important: Your card will not be charged, only verification." Microsoft would never require credit card information in order to check the legitimacy of some of its Windows copies.
Provided that you do not trust this information, and try to close the window, it stays on the background. It turns out that the only way to remove it from there is to eliminate the malware pieces responsible for its initial appearance.
This malicious software exploits vulnerabilities found in the targeted computers in order to invite itself in their systems. Since vulnerabilities are mainly caused by not-updated software, make sure to keep all your programs updated by downloading their updates from their official websites only. Another good prevention strategy is to stay away from any suspicious websites, since they might be hiding a virus, just like in the case with this fake Windows Registration Checker.
As soon as the malware slips into the machine, its window gets stuck on your desktop background. It is not only annoying, but also very dangerous, since it can lead to the download of additional viruses. Therefor, it is highly advisable that you run a full scan of your system with a legitimate anti-virus software and remove the fake Windows Registration Checker immediately.