This number is being given out by scam callers, claiming to be from Windows, about computer problems. When I asked where the caller was, he said Sydney, Australia. The number on caller ID, with 12 digits, was obviously not Australian. When I pointed this out, he gave me the 1800 number, and when I asked what would happen when I called this number, he told me it would reach Windows Security. I told him that it was a scam, and that all contact with Microsoft has to be client initiated, and hung up. I called the 1800 number, which was answered by another Indian voice, who answered 'Windows Security, how may I help you?'. I hung up. The scammers are obviously getting more sophisticated.