I'm sorry about the issue. Please ignore / close that message. That is a scam; they just want your money.
Is there any application or anything not working on your computer right now?
Can you please shut down / restart the computer, then see if that message still shows up or not?
If needed, please download the Malwarebytes Anti-Malware application at the website below and use it to scan your computer:http://www.adwaremedic.com/index.php
Please reply at the box below to continue troubleshooting. Thank you.