Beware of a telesales scam where cold callers are phoning people claiming to be from 'Windows Operating Services' or other support company. It's happening right here in Darwin!
The scammers ask you to open Event Viewer in Windows (which is an area that maintains logs/events in your system). It is quite normal for this event viewer to display error messages. The scammers try to convince you that those error messages prove that your computer has a virus and then offer to help you. If you agree, they will access your computer remotely, tinker around on it for awhile - and then present you with an invoice for their services.
I read an article about this scam in a tech magazine published in London, but recently a friend of mine in Humpty Doo, NT received a very similar phone call so it prompted me to issue this warning.
Many (if not most) people would be suspicious straight away, but for those less computer savvy and in particular if you happen to really have a problem with your computer, you might believe a Windows support phone call is reasonable.
For more information, please see the Microsoft News Centre article.