If your PC is running Windows XP, Windows Vista, or Windows 7 you will qualify to download an upgrade to Windows 8 Pro for just US$39.99. This offer will be available across the world in 131 markets.

Upon visiting Windows.com users can purchase an upgrade to Windows 8 Pro using the Windows 8 Upgrade Assistant.

Once Windows 8 has been downloaded users will be able to create their own bootable U
SB or .ISO file which can be burned onto a DVD for upgrade and backup purposes. There is also the option to purchase a backup DVD for US$15 plus shipping and handling.

A fully-packaged DVD version of Windows 8 Pro will also be available for US$69.99 throughout the promotion.

Picture courtesy of The Register UK

The Windows 8 upgrade offer will run until 31 January 2013.

Prices for system builders

If you’re not upgrading from a prior version of Windows and are building your own PC or installing Windows 8 in a virtual machine or a separate partition, you will be able to purchase and install the Windows 8 and Windows 8 Pro System Builder product instead.

Get Windows Media Center for free

After upgrading to Windows 8 you will be able to add Windows Media Center for free through the “add features” option in Windows.