Claims to be calling from Microsoft Windows and says he is responding to the errors they have been receiving from my machine. When asked what email he was receiving the error messages from, he said none - it was from the remote process that is used for Windows updates. I indicated I was not receiving any errors. He then wanted to set up a remote session so he could point out the errors. Realizing this was a scam, I said I was not going to do that and I hung up.
WARNING - DO NOT ALLOW THEM TO CONNECT REMOTELY - they can make a copy of your information and steal it!
I wasn't home so they got my voicemail. The message claimed to be the IRS and they would be putting a lien on my assets for unpaid debts. They left an 866 number to call back, but I won't be doing that. I have paid the IRS faithfully all my working life. The message said it was leaving a message for "your name" so that tells me that they don't even know who they are calling.