Microsoft's new operating system has now gone on pre-sale pre-order in countries across the globe, including the UK.

Windows 7 will be generally available in the UK on 22 October, but for those that want to make sure they nab a version at is lowest pre-order price, Microsoft says "stocks are limited and it is first come first served!"

Limited stock nonsense aside, getting the OS for £49.99 for Home Premium or £99.99 for Professional, rather than the full prices of £169.99 and £219.99, if you know you want or need it, is not to be sniffed at.

Various UK retailers are offering the new OS under the promotional pre-order scheme, including Amazon.co.uk, Argos, Comet, Currys, Dixons, Ebuyer.com, John Lewis Partnership, Littlewoods, Micro Anvika, PC World, Play.com, Staples and Tesco.

Alternatively there is more info at www.microsoft.com/uk/win7preorder.