The methods of spammers or computer criminals can be convincing especially when they pretend to be calling on the phone from Microsoft.
I’ve had these types of calls myself. They claim to be from Microsoft calling to inform the user the PC is infected by a virus. They offer to do a remote inspection to confirm the threat and either seek an IP address (the address of your PC on the internet) or direct the user to a spoofed Microsoft website to download a tool so the caller can take over the machine remotely.
If they want an IP address you could give them DOCEP’s DNS server address at 22.214.171.124. If they ask you to visit a Microsoft website and you are using IE8 you can see in the URL area that the main domain (microsoft.com) will be in bold, while the rest of the URL is greyed out.
But this is a lot to remember on the spot. Best to remember that Microsoft will never make an unsolicited call to you for any reason, especially if it involves remotely accessing your PC and eventually asking for money. Just as winning a lottery that you never entered in the first place is highly unlikely, so will be a friendly suppport call from a Microsoft engineer on another continent be unlikely.