Someone got 26 years of Windows running on a classic IBM ThinkPad T43 without a virtual machine

A Reddit user, MatiHalek, installed and upgraded nearly every major Windows release from NT 4.0 to Windows 10 22H2 on an IBM ThinkPad T43, all on bare metal.

The process used a mix of dual-boot and in-place upgrade paths, and ended with a multi-boot setup for the older Windows versions.

Windows 11 was not a practical option because the T43’s 32-bit Pentium M hardware isn’t suited to it.

The result highlights how surprisingly broad Windows compatibility can be on late-IBM ThinkPad hardware, and why it remains useful for retro testing.