While we already know how much it will cost users to upgrade to Windows 8 Pro in some markets, today Microsoft has finally revealed the price for those in the UK. Anyone who purchased a Windows 7 PC since June 2nd of this year will be able to download the upgrade for £14.99 through windowsupgradeoffer.com. Meanwhile, starting October 26th, those with older Windows machines can expect to pay an estimated retail price of £24.99 to download the upgrade. If you're unsure about making the jump to Windows 8, be sure to check out our preview of Microsoft's latest operating system.