Microsoft launched Windows 8 in the fall with attractive pricing — just $39.99 for Windows 7, Vista or XP users — but come February the price goes up. Way up.

After the promotional upgrade offer ends on Jan. 31, anyone running an older version of Windows will have to pay $119.99 for the privilege of running Windows 8, a Microsoft blog post reveals. And that's just the basic edition; if you want Windows 8 Pro, it'll cost you $199.99.

While it's a steep increase, jacking the price up on Windows 8 upgrades makes some sense. Although Microsoft has provided few details about how many machines are actually now running Windows 8, reports suggest the platform isn't performing as well as expected. By giving users a deadline, it encourages anyone on the fence to buy now, potentially giving adoption of the new OS a final big push.

SEE ALSO: The Problem With Windows 8

The new pricing plan has options than just the basic and Pro upgrade products. If you buy a PC with basic Windows 8 and decide to upgrade after the deadline, that'll cost you $99.99. And Windows 8 Pro users can add Windows Media Center and DVD playback via the Media Center Pack for $9.99.

If you're building a PC from scratch, none of these options are what you're looking for. Microsoft says you'll want the Windows 8 System Builder — a product usually reserved for OEMs — which typically runs around $100-$165.

If you're interested in upgrading to Windows 8 for cheap, there's still time. Windows 8 Pro costs just $40 for the next 13 days, or if you really want the DVD copy, you can buy one at retail for $69.99.

The full breakdown on the new pricing is below. Tell us what you think of Microsoft jacking up the price in the comments.

Windows 8 Pricing After Jan. 31:

Windows 8 Pro upgrade edition (for Windows 7, Vista and XP users): $199.99

Windows 8 upgrade edition (for Windows 7, Vista and XP users): $119.99

Windows 8 Pro Pack (for Windows 8 users): $99.99

Windows 8 Media Center Pack (for Windows 8 Pro users): $9.99

Windows 8 System Builder (for DIY PC builders): $100-$165

BONUS: A Tour of Windows 8

Windows 8 Review

Photo courtesy of Microsoft