MS Task Manager turns 30: Creator reveals how a 'very Unixy impulse' endured in Windows

As Microsoft's Task Manager celebrates three decades - and grapples with its modern tendency to leave orphaned processes behind - its creator has shared the story of how the much loved troubleshooting tool came to be.

Dave Plummer, a former Microsoft engineer, says his lean original has grown roughly 50 times in size. Rather than critique today's version, Plummer took to his Dave's Garage YouTube channel to offer a window into Task Manager's scrappy origins, including the thought process behind its development, and his unfortunate decision to include his home phone number in the source code.

"The birthday is stamped into the code itself: November 10, 1995," Plummer said.

Task Manager emerged from what Plummer called "a very Unixy impulse" - he wanted to see what was running on his system. Windows NT had the architecture to surface that information but no dashboard. So he built one.

"What happened next could really only have happened in that 1990s Microsoft era when the company still ran on caffeine and bravado."

Plummer brought it in. The NT team liked it. Dave Cutler himself, then the leader of NT development at Microsoft, tried it, liked it, and gave the team the green light to ship it.

Not everyone was thrilled. Cutler had Plummer put Task Manager at the top of the Start Menu, horrifying the Windows 95 team, whose vision of a clean and simple interface had been despoiled by abject nerdery. "Some wanted it pulled," said Plummer. However, Task Manager also had its champions, and the code eventually found its way into the source tree.

As his first complete application, Plummer approached Task Manager carefully. "When I'm new to something, I do it carefully and try to follow all the rules. It's because I don't know enough to take any shortcuts yet."

The result was a compact and reliable application. He noted the NT 4 Task Manager is only 85 kilobytes and remains functional today.

Committed to accuracy, Plummer discovered a bug where CPU totals occasionally exceeded 100 percent. The kernel team was "unsympathetic" to his suspicion that NT's process accounting was at fault.

So he instrumented an assertion to trip if the sum crossed 100 percent and added his home phone number so testers could call him if it happened. Then a beta build shipped with the message before he could remove it.

The kernel bug was real and eventually fixed. Plummer commented out the message, but the number - which he still has today - remains in the source code. "Please don't call."

Early Task Manager versions could bring Windows to its knees if users gave processes real-time priority or trigger Blue Screens of Death. But Plummer didn't see preventing user choices as his responsibility.

"I believe the operating system should be the arbiter of what's allowed, and that my job was not to second guess it."

Thirty years on, Task Manager endures. As for what was the most important line of code? It isn't a line, according to Plummer. It's a habit.

"It's the habit of eating your own dog food and accountability that says if a number is wrong or a window flickers, I take it personally until the fix ships. He added: "It's a product of a time and a culture that allowed ownership over time to translate into craftsmanship.

"It's the habit of assuming that the user is trying to accomplish some real work. Ship a build, make a flight, save a document, and my job is to just fix things and get out of the way.

"And it's the habit of resilience. If the tool itself gets stuck, revive it. If the system is starving, work in reduced mode," Plummer said. "If the user needs a chisel, don't give them a Nerf bat." ®