The Trojan Spyware alert below, which claims access to potential victims' PCs has been blocked for security reasons, is a fake and phishing scam. The scam attempts to trick potential victims into calling scammers/cybercriminals at the fake Microsoft Customer Support telephone number 1-(866)-993-1836, by falsely claiming their PC has become infected with a Trojan. Therefore, online users who have received the alert are asked not to call the fake Microsoft Tech Support number in it, because Microsoft will never ask Windows users to call them when they find a virus, Trojan, or malware on their computers.
The Trojan Spyware Alert Scam

Your computer has alerted us that it has been infected with a Trojan Spyware. The following data has been compromised.
Windows Defender Security Center
App: Ads. fiancetrack(2).dll
Threat Detected: Trojan Spyware
Access to this PC has been blocked for security reasons.
Contact Windows Support: +1-(866)-993-1836(Toll-Free)
Windows Deny Allow
If the fake Microsoft Customer Support telephone number in the scam alert is called, scammers will pick up and pretend to be from Microsoft. They will attempt to trick the caller into giving them remote access to their PCs. If this is done, the scammers will silently install spyware on the victims' PC. With spyware installed on their potential victims' computers, they will steal their personal and financial information, which they will use fraudulently.
If you were tricked by the Trojan Spyware Alert scam and were asked to install software on your PC, please have a tech-savvy person or a professional scan your computer for spyware. And, it is recommended that you change all your online passwords.