Microsoft released the very first version of Windows nearly 25 years ago, but the chances are you don't remember it. We talk to some Windows 1.0 users who recall their experiences.
Guy Gilbert, a Microsoft group product manager, first encountered Windows in the early 1990s, and used it to run Excel and some presentation software.
Switching between Windows and more rudimentary systems was frustrating, Gilbert says.
"It was still a world where you did part of your work in Windows and there was still a good chunk of your work you were doing on the mainframe," he says. "I was an analyst at Exxon Mobil in the early '90s, spending a lot of time with Excel, which was great, and then you had to go back to their proprietary email system which was on a mainframe, which was really horrible. Things like attaching a document were so horrible compared to the graphical user interface [of Windows]," he says.
Despite joking about his first encounter with Windows, Bryan says he was impressed.
"I was impressed because I had been using all text interfaces. It's a pretty big change, to go from having to type everything in to point and click," he says. "It was a metaphor change, it was a way of interacting with computers in a much different way."
Windows was particularly helpful to those who might be called computer-illiterate.
"It made it accessible for a lot more people," Bryan says. "I remember buying a [DOS] computer with my family for the small business they had. ... I was excited and telling them about what they could do with the PC and then we turned it on and it comes up with a flashing A prompt. Well what do we do now?
"It's so intimidating to start off at a command prompt, with just like a blank screen and a blinking cursor with an A, and people have no idea what to do. They're just like 'I guess we turn it off now.'
"But with Windows you click over here and you're in the program. ... It definitely was a revolutionary change in terms of the experiences people had and the accessibility it brought to so many more people."
See also: The nine best free Windows 7 downloads