All good things have to come to an end, and today marks the last opportunity for Windows users to upgrade to Windows 8 at a discounted rate. Since Microsoft's next-generation OS released back in October, a Windows 8 Pro upgrade has been available for $39.99, but from tomorrow onwards the same upgrade will set you back $199.99. If you've been dithering over whether to upgrade, now would be a good time to make a decision.

Assuming you're interested in Windows 8 at all, it's worth noting that you wouldn't have to install it right away. As long as you have enough hard drive space, you can buy it, download the image file, and save it for a later date.

As well as the $199.99 Windows 8 Pro license, Microsoft is offering a regular Windows 8 upgrade for $119.99. If you decide you want to upgrade to Pro at a later date, it'll set you back $99.99. The final change in Microsoft's pricing structure concerns Media Center. Presently, Windows 8 Pro lets you add Media Center at no additional cost, but from tomorrow onwards those same features will cost $9.99 from the Windows Store. This change doesn't just affect new customers; current Windows 8 Pro users must claim and use their free Media Center key before tomorrow, or pay the same $9.99 fee at a later date.