I just received a call from Microsoft located in Las Vegas, the man had a very broken accent, telling me that I have a Microsoft Computer problem and I should be sitting at my computer for further instructions. I told him I have a Dell computer with Windows 7, but he insisted I had a Microsoft computer and was calling to fix a Microsoft problem. Are you aware of Microsoft actually contacting customers to fix a problem with Microsoft? He was very persistent and called back again after I told him I would not participate. This is probably the third call I have received. I would be very interested to know the circumstances of this call.
Carolyn, you are smart to be suspicious. To quote a very wise person, Judge Judy in fact : “If something doesn’t make sense, then it’s not true.” Nothing about this call makes sense. How would Microsoft even have your phone number? And how would they know if there was an issue with your computer? Issues with Windows are fixed using update available in the Windows update center, not by calling people up on the phone.
You’d have a hard enough time getting in touch with someone at Microsoft if you called them for help, so they aren’t calling up people at home out of the blue to fix issues on their computer. Your caller is not one of the cheerful coffee-drinking Microsoft employees the company displays in the careers section of their website, but a scammer. (most likely calling from overseas.)
Carolyn, you should report these calls to the police. This persistent scammer is targeting you.
Microsoft warns about a scam just like this on their website. 
They scammers claim to be Microsoft and offer to solve computer problems. Sometimes they try to sell you a software license. They might also trick you into installing malicious software that steals your date or passwords, take control of your computer remotely, ask for your credit card information or direct you to fraudulent websites.
Microsoft does not make unsolicited phone calls and neither do any of their offiical partners.
Here are some of the organizations that cybercriminals claim to be from:
Windows Service Center
Microsoft Tech Support
Windows Technical Department Support Group
Microsoft Research and Development Team (Microsoft R & D Team)
Other common scams using the Microsoft name involve asking for credit card information to validate your copy of Windows, unsolicited e-mails from Microsoft with attached security updates and notices that you have won the Microsoft Lottery.
When you get a call like this, don’t purchase any software or services. Never give control of your computer to a third-party unless you are sure it is a representative of a company that you have hired for customer support. Never give out your credit card information.
You can call your local police to report these calls and you can also file a complaint with the Federal Trade Commission by clicking here. 
If by chance, someone does give out too much information to a caller like that, he or she should immediately change their computer’s password, scan for malware and contact their financial institution.
The only exception to the no calls from Microsoft rule is that rarely they will work with Internet service providers to fix a large-scale issue. In that case the call would come from your ISP and it would be easy to verify that you are a customer.
I’d suggest calling the police, notifying the FTC or perhaps blowing a whistle into the phone next time these people call.