Owners of Windows Vista Ultimate SP1 Promotional Software Kits can now head over to the RegisterWindowsVistaSP1 website and enter the unique PIN from the copies they were handed, along with their email address, and Microsoft will offer them a product key. For those of you that missed that deadline, it has now been extended until June 30, 2009. So if you still have a kit and didn’t register it, please go do it now and have the product ID emailed to you, revealed Keith Combs.