Despite any doubts concerning Windows 8 and its infamous Start screen, lots of people will be jumping on board today. For those still on the fence, Microsoft’s limited-time upgrade discounts will be a tempting reason to make the switch.Until January 31, 2013, the boxed retail edition costs $70, while a digital download version is available through Microsoft’s Windows Upgrade Assistant for $40. Windows 7 PCs purchased between June 2, 2012 and January 31, 2013 get the best deal of all, however; just register for a promo code by February 28, 2013 and you can upgrade your new Windows 7 machine for a mere $15. If you’re ready to become an early adopter, here’s what you need to know before moving to Windows 8.RequirementsThe Windows 8 setup process will check your system for compatibility, but the modest hardware requirements are as follows:Processor: 1GHz or faster with support for PAE, NX, and SSE2RAM: 1GB for the 32-bit version, 2GB for the 64-bit versionHard disk space: 16GB for the 32-bit version, 20GB for the 64-bit versionGraphics card: Microsoft DirectX9 graphics device with WDDM driverKeep in mind that those are the minimum specs. If you want to run Windows 8 well you’ll want to have a little more where it comes to processor speed and memory. The computer you’re upgrading will need to have Windows XP (SP3), Windows Vista, or Windows 7 installed. The version you’re coming from is important, since it determines how much can be transferred over:Windows 7: Windows settings, personal files, and programsWindows Vista (SP1): Windows settings and personal files (If you don’t have the service pack, you won’t be able to transfer settings)Windows XP (SP3): personal files onlyAlso note that you can’t jump between 32 and 64-bit when upgrading. So if you’ve got a 64-bit processor and want to bump up to a 64-bit OS, you’ll have to buy the boxed Windows 8 System Builder and do a full install. If you’re going the digital route, you’ll of course need an Internet connection and some time for the download to complete. Microsoft estimates that the whole package will be about 2GB, and will require around 90 minutes to complete over a broadband connection. Finally, make sure you have your old Windows product key on hand in case the upgrade install asks for it.Backup your filesI’m sure the Windows 8 installer works well, and that it’s perfectly capable of transferring your personal files over during the upgrade. But when you’re dealing with important data, you can’t be too careful. Before upgrading, make sure you’ve got all the documents, pictures, game saves, and anything else you need backed up to another drive or your cloud storage service of choice.Option 1: Digital downloadDownload and run the Windows 8 Upgrade Assistant to get started with the digital download. If you’re doing the $15 upgrade option, don’t get thrown off when you see the $39.99 price show up in the Assistant; once you go into the order screen you’ll have an option to enter your discount code.If you want a physical upgrade disk, you have a couple of options. When you purchase the upgrade through the Assistant you’ll be able to get a disk mailed to you for $15; even if you’re paying the full $40 for the download, that’s still cheaper than buying a boxed copy. You can also put the installer on your own writable DVD or USB drive using an option in the Assistant.Option 2: Boxed copyIf you like getting your software the old fashioned way, or feel more comfortable buying a boxed product, you’re going to have to pay a bit more. Currently Amazon has one of the best deals, though: a $30 promotional credit if you purchase the upgrade before October 27. Just make sure that you buy the upgrade version, which is labeled “Windows 8 Pro.” The “System Builder” edition is for doing a fresh install on a new machine, and the “Pro Pack” is for bumping regular Windows 8 up to Windows 8 Pro.With both the physical and digital upgrade options, the install interface seems straightforward enough, and it provides information on what will be transferred and which of your programs will be compatible with Windows 8.No matter what the final verdict on Windows 8 is, it’s nice to see Microsoft making the upgrade process easier and cheaper than ever before.