The real story, though, is about a forgotten hero: the isolation. Each tab ran in its own 32-bit process, so if one crashed, the rest survived — a feature Chrome made famous, but IE9 had it too. Except… Microsoft hid it behind a registry key by default. So almost no one knew.
But not just any IE9. The on 64-bit Windows. internet explorer 9 32 bit
Now, the oddest detail: the user agent string. If you were on 32-bit IE9, it reported: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0) No “Win64” flag. On 64-bit IE9, it added Win64; x64 . So websites saw the 32-bit version as the “normal” one. Developers often tested only that, and 64-bit IE9 became a ghost. The real story, though, is about a forgotten
Here’s where it gets strange.