Microsoft this week opened up the registration for its Windows Upgrade Offer, which allows purchasers of qualifying PCs based on Windows 7 to later upgrade to Windows 8 Pro for just $15. Now, you can register for the program online and await your upgrade, which will become available on October 26 when Microsoft launches Windows 8.

“If you purchase or have purchased an eligible Windows 7 PC anytime between June 2, 2012, and January 31, 2013, you will be able to purchase an upgrade to Windows 8 Pro for only $14.99 (US) which will be redeemable when Windows 8 is generally available on October 26th,” a post to the Blogging Windows blog notes. “Registration for the Windows Upgrade Offer is only for those who buy an eligible Windows 7 PC between June 2 and January 31, 2013.”

Microsoft announced the Windows Upgrade Offer in May, noting that this consumer offer would be available in more than 130 markets around the globe, including the United States and Canada. Those who have registered for the offer will be able to download Windows 8 Pro starting the day it’s made generally available—October 26—or order a DVD if they prefer old-school media.

To get started, visit the Windows Upgrade Offer website once you’ve purchased a new PC and get registered.

If you’d rather purchase an upgrade version of Windows 8 for a PC purchased before June 2, Microsoft is also offering a $40 upgrade to Windows 8 Pro. That offer will go live on October 26, Microsoft says.