More than 1 billion PCs in use today
Gartner analysts also revealed that they expected the number of PCs in use to hit 2 billion by 2014, with a 12% annual increase, largely thanks to the surge in adoption rate in developing countries.
One of the greatest challenges that countries will also face in the future is figuring out how to safely dispose of unwanted computers. It is estimated that some 180 million computers, or about 16 percent of those in use globally will be retired. and up to 35 million will be “dumped into landfills with little to no regard for their toxic content”.

Its all well and good that you’re upgrading to the latest PC capable of playing Crysis, but do remember to dispose of your old PC more responsibly, k? Cos the Earth will love you for that.