If you haven't ever played Solitaire, Minesweeper, Hearts or FreeCell, it's safe to say you're in the minority. These simple Windows games have probably caused more lost worker hours than anything short of a worldwide coffee shortage. Whichever one was your favorite, the temptation to take just one more go at beating them—to get a faster time or a better score—was hard to ignore.

But as fun as these games were, they weren't actually designed for entertainment. At least not in their Windows incarnations.

The oldest of the four, Microsoft Solitaire, was first added to Windows 3.0 in 1990. Although the game (sometimes called "Patience") has existed since the late 1700s, this digital version seemed to be demonstrating that in the future we would no longer require a physical deck to play simple card games. But that's not what it was doing at all. Its real aim was far more modest: it was teaching mouse-fluency by stealth.

The intention was that Solitaire would get a generation of computer users still most familiar with a command-line input to teach themselves how to drag and drop, without realizing that's what they were doing. The fact that we're still dragging and dropping today suggests that it worked rather well.

Minesweeper, too, has a similar place in technological culture. The numbers-based logic puzzle has roots in the mainframe gaming scene of the 1960s and 1970s, where a version called "Cube" by Jerimac Ratliff became incredibly popular. Decades later, in 1992, the Microsoft version Minesweeper was introduced to Windows 3.1—not to demonstrate that Windows was an adept gaming operating system, but to make the idea of left and right clicking second nature for Windows users, and to foster speed and precision in mouse movement.

If you needed any proof that this isn't a coincidence, look at another Microsoft card game: Hearts. It was introduced with 1992's Windows for Workgroups 3.1—the first network-ready version of Windows—and used Microsoft's new NetDDE technology to communicate with other Hearts clients on a local network. Again, this wasn't just a card game. It was a way to get people interested in (and hopefully impressed by) the networking capabilities of their new system.

And finally, there's FreeCell. Released for Windows 3.1 as part of the Microsoft Entertainment Pack Volume 2, FreeCell was bundled with the Win32s package that allowed 32-bit applications to run on the 16-bit Windows 3.1. Its purpose was actually to test the 32-bit thunking layer (a data processing subsystem), which had been introduced as part of Win32s. If the thunking layer was improperly installed, FreeCell wouldn't run. So what you thought was a game was actually a stealth test of software systems.

Of course, none of this explains why those games persisted once their remit was fulfilled. The answer is simple: people had too much fun with them. Any time Microsoft tried to remove the games from a release of Windows, testers went crazy. Eventually, in 2012, Microsoft released a version, Windows 8, without any of the games. Users could download the Solitaire Collection and Minesweeper separately, but you had to pay extra to play without ads.

However, with this year's release of Windows 10, Microsoft has at least brought back Solitaire. If you go looking for the others in your search bar, you'll instead be shown search results from the Windows Store where you can download the latest versions. And maybe that's intentional, because what better motivation do you need to learn how to use the Windows Store than to get your hands on your favorite games? Maybe they're still teaching by stealth, even after all these years.

This post originally appeared on our UK site.