Windows 7 is the easiest, fastest, and most engaging version of Windows yet. Better ways to find and manage files, like Jump Lists and improved taskbar previews, help you speed through everyday tasks. Faster and more reliable performance means your PC just works the way you want it to. And great features like Windows Media Center and Windows Touch make new things possible. Get to know Windows 7, and see how it can simplify just about everything you do with your PC
Keep in mind these are without any kind of cracks / activations. There are some beta activators floating around, but most of them are using RC pkeyconfig.xrm-ms & tokens.dat files. That means if you activate Windows 7 on that way (with RC Keys available from Microsoft) they�ll expire on March 2010. But if you ask me, better that than 30 days.

Size: 2.33 GB (x86)

The purpose of activation key in Windows XP, is to reduce the illegal copying and intended to curb software piracy,
It might requires every user to connect Microsoft via the web to obtain a long product support after installation.

In theory, only once you have to activate it. But the activation code is just as susceptible to bugs as any other component of Windows.

If you don't enter the product key within a certain period after installing, your Windows XP will expire, and will cease to function.

The keys is generated by Microsoft a long sequence of numbers based on a information found in your computer's hardware. This ensures that one person's key will not work on another system.

But what if you don't have the activation key yet?

Don't worry about that since there are many way to activate XP without contacting Microsoft and there are lots numbers of "cracks" on the web that reportedly circumvent the activation.

This is a bundle of "crack" that I've been collecting from the net...