Colin from Western Australia writes:
I am a longterm user of Win XP and realise I have to give it up soon. Some years ago I bought a copy of Vista but never used it – it just sits there sealed but gathering dust. Would it be safe and fully usable to have Vista installed as my OS?
Colin, I don’t see any reason why it wouldn’t work as long as your system is compatible and you have the product key. Mainstream Microsoft support for Vista ended in 2012, but the extended support will run until April of 2017. The good news is that you can upgrade to Windows 7 if you like for a little over a $100. (That’s the cost in the U.S. I’m not sure what the price might run you in Australia.) Mainstream support for Windows 7 runs until January of 2015 and extended support is promised until 2020.