Windows 95 Released

Midnight, 24 August 1995. Across North America and Europe, queues had formed outside electronics retailers for the midnight launch. The Japanese-language edition came three months later, on 23 November; UPI described tens of thousands of people converging on Akihabara that midnight, amid balloons, music and people dressed as computers.

The night is often called the moment the PC became a household appliance.

Chicago Was Four Projects

Windows 95 was code-named Chicago, and that name was applied late. As Raymond Chen has recounted, its major components were already separate projects, each with its own code name, "by the time somebody decided to combine them into one giant project":

Three ferocious cats and a cartoon one. The shape of the shipped product follows directly from that inheritance: Windows 95 is not a 32-bit operating system that grew a compatibility layer, it is a merge, and every architectural compromise below is a seam in that merge.

What the 32-Bit Transition Actually Changed

Technically, Windows 95 sat between Windows 3.1 and Windows NT: protected-mode 32-bit code, long file names, Plug and Play hardware detection. Microsoft's own architecture documentation summarises the gain as "a fully integrated 32-bit, protected-mode operating system, which eliminates the need for a separate copy of MS-DOS."

For an application, three things changed at once.

Addressing. Windows 3.1 applications lived in segmented 16-bit memory: an address was a segment plus an offset, and one segment spanned at most 64 KB, so the boundary was a working constraint on every large data structure. Windows 95 gave each process "a unique virtual address space of 2 GB", flat and linear, addressed with 32-bit pointers, on a demand-paged virtual memory system: the lower 2 GB private to the application, the upper 2 GB shared. Segment arithmetic simply left the programmer's vocabulary.

Scheduling. Windows 3.1 multitasked cooperatively: the operating system "required an application to check the message queue periodically and to relinquish control of the system to other running applications," and one program that did not check would, in Microsoft's own phrase, "hog" the CPU. Windows 95 scheduled Win32 applications preemptively and gave them threads — a Win32 process could paginate a document in one thread while the user typed in another, where a Win16 application had to hand-roll its own scheme.

The seam. All of that applied only to Win32 code. Windows 95 has one System VM in which all system processes and both Win16 and Win32 applications run; only MS-DOS applications get a VM each. And "for compatibility reasons, Windows 95 cooperatively multitasks Win16-based applications." So loading one legacy program returned that program's neighbours to 3.1-era stability, and the kernel's own translation layer — thunking, mapping 16-bit values to 32-bit and back — sat in the path of the 32-bit system libraries themselves.

Long file names came from a different piece of the merge: a layered, installable file-system architecture (VFAT, CDFS, network redirectors) that let users "specify up to 255 characters" instead of MS-DOS's 8.3.

But it was not these advances that put people in the queue. It was that Microsoft, for the first time, sold Windows in a form that looked interesting to people who were not personal-computer enthusiasts.

• Blue sky and clouds — the brand image carried across the boot screen, the box and the advertising (the default desktop background was in fact plain teal; the clouds wallpaper was one of the bundled options)
• The Start menu in the lower left, the taskbar beside it
• A startup sound composed by Brian Eno. Microsoft's brief specified 3.25 seconds; what came back was roughly six seconds of ambient music
• Three icons: the Recycle Bin, My Computer, Network Neighborhood

For the next twenty years, no matter how Windows evolved, these would remain the core of what 'Windows' looked like.

"Start Me Up"

Microsoft built the campaign around the Rolling Stones' 1981 Start Me Up. The licence fee was reported for years at somewhere between $8 million and $14 million; in 2011, Microsoft's chief operating officer of the period, Bob Herbold, put it at about $3 million. That the figure ran loose for sixteen years says as much about the launch as the number does.

The message was direct: press 'Start' and an OS begins. Selling a software release with the advertising grammar of cars and perfume was, for the industry, new.

Internet Explorer

The Windows 95 box did not contain Internet Explorer. IE 1.0 shipped inside Microsoft Plus!, a paid add-on released the same day — sold separately, but not delayed.

A year later, Windows 95 OSR2 (1996, OEM channel) bundled IE 3.0 by default. Ahead lay the bitter contest between Microsoft and Netscape, and the antitrust suit the US Department of Justice and twenty state attorneys general filed on 18 May 1998. Windows 95 was the starting line of a ten-year legal struggle over the relationship of operating system and web browser.

Seven Million

By Microsoft's own count, Windows 95 sold seven million copies in its first five weeks. At the one-year mark in August 1996 the company announced that 40 million units had shipped worldwide.

The same release is more interesting for the second-order numbers, because they describe an ecosystem rather than a product:

• more than 400 PC manufacturers licensed and shipping Windows 95, including all of the top 100 makers of Intel-based PCs
• more than 20,000 PC manufacturers and assemblers shipping it in total
• more than 3,000 Plug and Play devices available
• 4,406 software applications running on it, per Computer Select
• IDC forecasting that 67 per cent of PCs shipped in 1996 would include Windows 95, and an installed base of 70 million that year rising to 132 million in 1997

No packaged software had reached that scale before. Bill Gates would hold the top spot on Forbes' world wealth list for thirteen consecutive years, from 1995 through 2007.

The origin was a line of people in the dark, outside a retail store.