This is the cheapest upgrade for XP/ Vista I can find. Please note this is not the Windows 7 Starter Upgrade, that's a different product altogether. Dixons say...
This upgrade edition of Microsoft Windows 7 Home Premium can be installed directly over Windows Vista, or as a clean install with either Windows Vista or XP. The latter will require you to back up your files, and reinstall your applications. The upgrade package is not compatible with Windows 2000.
Microsoft Windows 7 Home Premium is a revolutionary new operating system that simplifies and greatly enhances your home computing experience. Full of refinements and performance improvements, this OS release supports the latest PC hardware developments such as multi-core processors and 64-bit computing. This really is an attractive upgrade for your PC!
After two years of customer research to discover precisely what users want from their computer, Microsoft engineered Windows 7 Home Premium around those expectations. The result is a sleek operating system that allows you to breeze through everyday tasks. For example, Windows 7 discovers USB devices quicker, lets you connect to and change wireless networks without complications, finds files anywhere on your hard drive nearly instantly, and much more!
Laptop computer users will very much appreciate the faster sleep and resume performance of Windows 7 Home Premium, as well as the improved power management features for extending battery life. There are also great new ways to manage files and windows! These include the new taskbar previews, bigger icons, Jump Lists for speedy access to your favourite files, and a Snap feature for resizing windows in an instant.
Overall performance has been improved too, reducing the memory requirements for Microsoft Windows 7 Home Premium and speeding up installation times. Windows Media Center now runs smoother than ever, with eye-popping visuals, stunning new slide shows, and brilliant new features for playing, pausing, recording and managing TV shows on your computer.
Best of all, the Microsoft Windows 7 Home Premium upgrade is amazingly affordable - ensuring that these great new features are accessible to everyone!