Windows NT

As we wait for this fall’s Windows 11 24H2 update to be released to the general public, work continues on other new features that could be part of other future Windows updates. A new Canary channel Windows Insider build released yesterday fixes a decades-old and arbitrary limitation that restricted new FAT32 partitions to 32GB in size, even though the filesystem itself has a maximum supported size of 2TB (and Windows can read and recognize 2TB FAT32 partitions without an issue).

For now, this limit is only being lifted for the command-line formatting tools in Windows. The disk formatting UI, which looks more or less the same now as it did when it was introduced in Windows NT 4.0 almost 30 years ago, still has the arbitrary 32GB capacity restriction.

The 32GB limit can allegedly be pinned on former Microsoft programmer Dave Plummer, who occasionally shares stories about his time working on Windows in the 1990s and early 2000s. Plummer says that he wrote the file format dialog, intending it as a “temporary” solution, and arbitrarily chose 32GB as a size limit for disks, likely because it seemed big enough at the time (Windows NT 4.0 required a whopping 110MB of disk space).

There aren’t a ton of reasons to actually use a FAT32 disk in 2024, and it’s been replaced by other filesystems for just about everything. As a filesystem for your main OS drive, it was replaced by NTFS decades ago; as a widely compatible filesystem for external drives that can be read from and written to by many operating systems, you’d probably want to use exFAT instead. FAT32 still has a 4GB limit on the size of individual files.

But if you’re formatting a disk to use with an old version of Windows, or with some older device that can only work with FAT32 disks, this tweak could make Windows a tiny bit more useful for you.

Listing image by Alpha Six

Windows 11 has done a lot to update and modernize long-neglected parts of Windows’ user interface, including many Settings menus and venerable apps like Notepad and Paint. But if you dig deep enough, you’ll still find parts of the user interface that look and work like they did in the mid-’90s, either for compatibility reasons or because no one ever thought to go back and update them.

Former Microsoft programmer Dave Plummer shared some history about one of those finely aged bits: the Format dialogue box, which is still used in fully updated Windows 11 installs to this day when you format a disk using Windows Explorer.

Plummer says he wrote the Format dialog in late 1994, when the team was busy porting the user interface from the consumer-focused Windows 95 (released in mid-1995) to the more-stable but more resource-intensive Windows NT (NT 4.0, released in mid-1996, was the first to use the 95-style UI).

Formatting disks “was just one of those areas where Windows NT was different enough from Windows 95 that we had to come up with some custom UI,” wrote Plummer on X, formerly Twitter. Plummer didn’t specify what those differences were, but even the early versions of Windows NT could already handle multiple filesystems like FAT and NTFS, whereas Windows 95 mostly used FAT16 for everything.

“I got out a piece of paper and wrote down all the options and choices you could make with respect to formatting a disk, like filesystem, label, cluster size, compression, encryption, and so on,” Plummer continued. “Then I busted out [Visual] C++ 2.0 and used the Resource Editor to lay out a simple vertical stack of all the choices you had to make, in the approximate order you had to make. It wasn’t elegant, but it would do until the elegant UI arrived. That was some 30 years ago, and the dialog is still my temporary one from that Thursday morning, so be careful about checking in ‘temporary’ solutions!”

The Windows NT version of the Format dialog is the one that survives today because the consumer and professional versions of Windows began using the NT codebase in the late ’90s and early 2000s with the Windows 2000 and Windows XP releases. Plenty has changed since then, but system files like the kernel still have “Windows NT” labels in Windows 11.

Plummer also said the Format tool’s 32GB limit for FAT volumes was an arbitrary decision he made that we’re still living with among modern Windows versions—FAT32 drives formatted at the command line or using other tools max out between 2TB and 16TB, depending on sector size. It seems quaint, but PC ads from late 1994 advertise hard drives that are, at most, a few hundred megabytes in size, and 3.5-inch 1.44MB floppies and CD-ROM drives were about the best you could do for removable storage. From that vantage point, it would be hard to conceive of fingernail-sized disks that could give you 256GB of storage for $20.

Plummer was involved with many bits and pieces of ’90s- and early 2000s-era MS-DOS and Windows apps, including the Task Manager, the Space Cadet Pinball game, and the first version of the product activation system that shipped with Windows XP. Plummer left Microsoft in 2003.

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