Microsoft’s Windows 10 is out Wednesday. That means the clock is now ticking for current users of Windows 7 and up, who will have one year from today to take advantage of Microsoft’s (MSFT) free upgrade offer.
Ready to make the move to Windows 10? Here’s a quick and dirty guide to installing it. As with all major upgrades, remember to back up your machine first. It’s also a good idea to check if your computer can handle the new software.
1. By now, eligible users should have seen a pop up notification on their desktop inviting them to “reserve your free upgrade” of Windows 10 (non-eligible users will have to either buy a new Windows device or pony up $119 for the Home version). If you haven’t already reserved a copy, do so, because that’s how Microsoft confirms your eligibility and starts prepping your device, quietly installing files on your computer in anticipation of the big download to come.
2. Soon you’ll see another pop-up notification to start the upgrade. It will look something like this:
Hit that notification, and the installation begins. Download times can vary from 20 minutes to more than an hour, depending on your device, which should give you more than enough time to read TIME’s Indispensable Guide to Windows 10 and hit the ground running. If you don’t see that notification, you can download Windows 10 right here.
Sign up for Data Sheet, Fortune’s daily morning newsletter about the business of technology.
