a screen came up on face book that said my computer may have a virus to call a # given

Hi Brutus26
 
Welcome to the Community Forums.
 
THIS IS A SCAM...whatever you do DO NOT call the number given.
 
EDIT: Apologies for the addition of additional information, after the initial response.  This is based on our standard reply produced by one of our gurus @  (see below) but I could not find it at the time of the initial reply and want to make sure that you did not consider responding to the 'invitation'.
 
No company, be it Microsoft, Facebook or any other company sends emails, pop ups, or phone calls of any kind advising that you may have a problem.
 
If you clicked anything links, allowed them to remote into your computer, or went to any web sites please submit a Trouble Ticket ASAP.  (Now would be a good idea....)
 
If you would like more information, read on (After submitting that Trouble Ticket.....)
 
NEWS ARTICLE: Tech Support Scams are on the rise.
 
 
Microsoft never issues this type of warning or email or anything of a sort!  Please see the following link for Microsofts official word on this:
http://www.microsoft.com/security/online-privacy/avoid-phone-scams.aspx
 
"Neither Microsoft nor our partners make unsolicited phone calls (also known as cold calls) to charge you for computer security or software fixes.
 
Cybercriminals often use publicly available phone directories so they might know your name and other personal information when they call you. They might even guess what operating system you're using.
 
Once they've gained your trust, they might ask for your user name and password or ask you to go to a website to install software that will let them access your computer to fix it. Once you do this, your computer and your personal information is vulnerable."
 
Also see Avoid scams that use the Microsoft name fraudulently
http://www.microsoft.com/security/online-privacy/msname.aspx 
 
 
For more information here iwhat the United States Federal Trade Commission has to say on the subject::
http://www.consumer.ftc.gov/articles/0346-tech-support-scams
 
"In a recent twist, scam artists are using the phone to try to break into your computer. They call, claiming to be computer techs associated with well-known companies like Microsoft. They say that they’ve detected viruses or other malware on your computer to trick you into giving them remote access or paying for software you don’t need.
 
These scammers take advantage of your reasonable concerns about viruses and other threats. They know that computer users have heard time and again that it’s important to install security software. But the purpose behind their elaborate scheme isn’t to protect your computer; it’s to make money."
 
This scam is common and has been around for quite a while.  Here is a good Webroot Blog article from April 2013 by Threat Researcher Roy Tobin.
http://www.webroot.com/blog/2013/04/30/fake-microsoft-security-scam/
 
Hope that helps answer the initial question and further informs you for the future?
 
Regards, Baldrick