Microsoft has revealed the price UK users will pay to upgrade to Windows 8 when the OS launches on October 26. Rather than the $39.99 our US cousins will be charged for Windows 8, UK PC and laptop users will have to shell out £24.99 - which works out at around $39 at today's exchange rate. See also: Windows 8 release date and features UK. Updated, 5pm, 29 August 2012.

Until the past couple of days the only hard information about Windows 8 pricing we had was that US users would be able to upgrade for just $39. Yesterday, however, Amazon UK started selling Windows 8 upgrade DVDs for £49, and this morning PC Pro reported a statement from Microsoft's UK press office that said the upgrade price would be be £39.99. Given that $39.99 is only around £25, at first glance this seemed like a massive rip off for UK users.

This afternoon, however, Microsoft said the initial statement had been incorrect due to an error in internal communications, and that the actual price would be £25. Pretty good news for UK users wishing to upgrate to Windows 8.

Because the US is a federation of states, each with its own tax laws, US prices typically don't include taxes, whereas the UK price is inclusive of VAT, at 20 percent. Take away VAT and the UK cost of Windows 8 is closer to £21 - cheaper than the US cost. Given that software makers typically point to the cost of shipping their goods to smaller territories as reasons for pushing up the price, as well as the cost of localising the software, this is a reversal of the usual trend of tech companies matching pounds to dollars and charging UK users more for the same product.

Shipping a few containers to the little old UK is a cost not incurred in holding stock somewhere in the US and then shipping to order. However, given that Windows 8 is likely to be delivered primarily as a download, and the localisation is included in all the code, these factors are a lot less valid for this OS than for previous Windows releases, which may have been reflected in the lower price.

An upgrade from XP or Vista to Windows 7 Professional will set you back £189, so Microsoft has set the Windows 8 price much lower that that of its predecessor. Pressure from Apple - which sells its OS X Mountain Lion for just £13.99, and a pressing need to disseminate it's new Windows Store to as many Windows users as possible are likely to have helped to make it an inexpensive upgrade.

Upgrading from Windows 7 to Windows 8 on a PC bought today will cost just £14.99 in the UK, subject to that offer being accepted at the time of purchase.

For more on the changes in Windows 8 and how to use them visit Windows 8 Advisor. For detailed advice on installing Windows 8 Release Preview, read our article: How to install Windows 8.