It sounds like you are encountering a tech support scam. The message you received is likely a fake alert designed to scare you into calling a number for help, which could lead to further issues, including potential scams or malware installation. Here are some steps you should take:
- Do not call the number provided in the message. Legitimate Microsoft error messages will never include a phone number.
- Close the browser if possible. If the message is preventing you from doing so, you may need to force close your browser or restart your computer.
- Run a full scan with Microsoft Defender Antivirus to check for any malware on your system. Make sure your antivirus software is up to date.
- Uninstall any suspicious applications that may have been installed as a result of this scam.
- Change your passwords for any accounts that may have been compromised.
- Monitor your accounts for any unusual activity and consider contacting your bank if you provided any financial information.
For more information on how to protect yourself from tech support scams, you can refer to the resources provided by Microsoft.