After 21 years, Windows XP’s activation algorithm is fully cracked

Microsoft may have sent Windows XP off into the great unknown in 2014, but the operating system never fully went dark. Never mind that yet two more versions of Windows have been put to rest since XP’s final days. Against the advice of just about everyone, the efforts to keep XP usable have continued on—as evidenced by recent news about a crack that enables offline validation of Windows XP product keys.

Previously, getting Windows XP to activate required circumventing Microsoft’s validation process or using a third-party server to fool XP. But as documented by tinyapps, a blog dedicated to floppy-drive-sized Windows programs, a new validation technique came to light last year. An app shared in a thread on the Windows XP subreddit not only performs Microsoft’s official activation process, but does so offline. Users can run the app freely, and afterward, they can reset the PC as much as they like without having to revalidate their copy of XP, too.

But as noted by The Register (which first spotted this news), virtually no one should be running Windows XP these days. While this crack is a lifeline for folks stuck supporting ancient software that only runs on an equally decrepit operating system, everyone else should be on a supported version of Windows (i.e., Windows 10 or 11). In its heyday, Windows XP had plenty of security issues—and now that it’s ostensibly in the grave, it’s even more vulnerable to today’s online threats.

That won’t stop the still-lingering resistance against migration, of course. But for the overwhelming majority of Windows users, you’re much better off leaving the past where it lies. If you must indulge nostalgia, you’re best off doing so briefly within a virtual machine—or just gawking at this news and then moving on.