Elena smiled. “Compatibility isn’t a certificate on a website. It’s whether the tool still does what you need.”

She clicked Install.

Then the license agreement appeared. In pixelated, early-2000s gray.

Twenty minutes later, AutoCAD 2010 launched on Windows 11. The classic dark gray workspace. The command line sitting patiently at the bottom. The old toolbars— not the ribbon—exactly as Mr. Hartwell remembered. It was slow. It complained about the graphics card. It crashed once when she tried to hatch a complex polyline. But for basic 2D drafting, it worked.

But she also remembered something: stubborn old software sometimes refused to die.

And for the rest of the afternoon, Windows 11 didn’t crash once.