WHAT A SURPRISE! This actually is the Microsoft switchboard. We received a call showing Microsoft Corporation as the caller. I thought, sure it is. Turns out it is a client who works at Microsoft and was returning a call from work. Glad I let it go to voicemail, because I would have been extremely snarky when I answered.
Be aware evil callers can send any number they want to your CallerID to mislead you. Unless you have previously initiated contact with Microsoft, it's extremely unlikely Microsoft will call you from out of the blue. May be a scammer pretending to be Microsoft. Be careful.
Please verify this, i have searched this no. and I found the link.
WHOIS - 65.54.61.76
Location: United States [City: Redmond, Washington]
Using 30+ day old [STALE - being deleted now] cached answer (or, you can get fresh results).
Hiding E-mail address (you can get results with the E-mail address).
OrgName: Microsoft Corp
OrgID: MSFT
Address: One Microsoft Way
City: Redmond
StateProv: WA
PostalCode: 98052
Country: US
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Mine was for Microsoft User testing that I signed up for. Apparently it's the "main phone line" for microsoft, but any of their billion employees that call you from Microsoft USA, the ID comes as that. the return number he gave me was his direct line.