Windows Vista has had everything but an easy ride since it hit the shelves in January 2007. The operating system was plagued by a luxuriant variety of problems from hardware and software incompatibilities to lack of support and poor performance and reliability. And in this context, Vista has also taken the users out for a ride, making every speed bump count, as Microsoft was applauding the evolved user experience delivered by its latest Windows client. Well, one of the most overlooked aspects among the vast volume of problems associated with Vista are the issues faced by end users when attempting to activate the operating system.

"Activation, also known as Microsoft Product Activation or Windows Product Activation, is an anti-piracy technology designed to verify that Microsoft software products are legitimately licensed. Activation works by verifying that the product key-the 25-character code located on your Certificate of Authenticity (usually affixed to your computer) or proof of license label (usually affixed to the installation disc case)-is authentic and is not in use on more personal computers than are permitted by the software license", reads a fragment of the Windows Vista Activation FAQ.

Activation is by no means a silver bullet solution designed to solve the piracy phenomenon, and as a matter of fact, it has been bypassed on both Windows XP and Windows Vista. But Microsoft continues to put end users through the pains of the activation process. And when you will see the extensive list of Windows Vista activation errors supplied by the Redmond company you will understand the use of the term "pain".

As the vast majority of users acquire Vista preloaded on an original equipment manufacturer machine, in November, Microsoft published a Knowledge Base Article 942962 referring to error messages that come as a consequence of attempting to activate Vista on an OEM computer. There are a total of three errors presented to the user:

"Error Code: Invalid Volume License Key - In order to activate, you need to change your product key to a valid Multiple Activation Key (MAK) or Retail key. You must have a qualifying operating system license AND a Volume license Windows Vista upgrade license, or a full license for Windows Vista through an OEM or from a retail source . ANY OTHER INSTALLATION OF THIS SOFTWARE IS IN VIOLATION OF YOUR AGREEMENT AND APPLICABLE COPYRIGHT LAW," as well as "Error Code: 0xC004F059 - Description: The Software Licensing Service reported that a license in the computer BIOS is invalid", and "Error Code: 0xc004f035 - The Software Licensing Service reported that the computer could not be activated with a Volume license product key. Volume licensed systems require upgrading from a qualified operating system. Please contact your system administrator or use a different type of key."

KB 942962 can be found via this link. But as far as end users as concerned, Microsoft gives a more complete view over the activation errors presented by its latest operating system in KB 931276. And corporate users are not spared. Volume Activation error codes on Windows Vista-based computers delivered through KB 938450 is nothing short of an encyclopedia of messages.