The upgrade from Home to Pro is quick and easy. Screenshot by Ed Bott/ZDNETIf you purchase a new PC with Windows 11 Home preinstalled, you might be able to get right to work. But for some demanding PC owners, this down-market edition doesn’t have some essential features, like the ability to connect to a Windows domain-based network, or to manage disk encryption, or to create virtual machines.Also: Yes, you can upgrade that old PC to Windows 11, even if Microsoft says no. These readers proved itTo get those features, you need to upgrade to Windows 11 Pro. (For a detailed list of Pro-only features, see “Here’s the best way to upgrade to Windows 11 Pro, and why you should.”) That’s a pretty straightforward process, but if you’re not careful, you can end up spending much more than you need to on the upgrade. And you can also find yourself having to do it all over again if you need to reinstall Windows.In this article, I cover three common scenarios for upgrading from Windows 11 Home edition to Pro. It all starts with one essential ingredient.First, you’ll need a product key for Windows 10/11 Pro If you’ve been building and upgrading PCs for a decade or more, it might be worth rummaging through your garage, storeroom, or email archives to see if you can locate a product key for Windows 10 Pro or Windows 11 Pro. (Yes, a product key for Windows 10 can be used to activate Windows 11 and vice-versa.)Also: Microsoft will start charging for Windows 10 updates next year. Here’s how muchOne option that used to work is, alas, no longer available. Previously, you could reuse an old product key from Windows 7 Pro, Windows 7 Ultimate, or Windows 8/8.1 Pro to enable an upgrade from Windows 10/11 Home to Windows 10/11 Pro, potentially saving you the upgrade fee. Microsoft closed that loophole in September 2023 when it finally ended its free Windows 10 upgrade program. If you purchased a retail copy of Windows 10 Pro and used it on an old PC that’s since been retired, you can freely reuse the key that came with it. (OEM copies that were preinstalled on the PC when you bought it aren’t transferable.) As an alternative, you can look for a discounted copy online. Microsoft’s retail price for Windows 11 Pro is $199 More