Bringing Modern Connectivity to Legacy OS
Windows 98 SE devotees can now enjoy experimental support for USB4 and Thunderbolt 3/4. Developer and maker Yeo Kheng Meng recently released the xHCI98 v3.0.0.0 driver, enabling the practical use of generic USB 3.x, USB4, and Thunderbolt 3/4 host controllers on systems running Windows 98 SE, ME, 2000, XP, Vista, and 7.
A demonstration video shows various USB devices being hotplugged to a modern 2020 ThinkPad P14s Gen 1 equipped with only an xHCI controller.
Addressing Missing xHCI Drivers
The project targets PCs from the mid-2010s that feature xHCI-only chipsets without legacy EHCI controllers. Because older operating systems lack native xHCI drivers, basic peripherals like keyboards and mice typically require BIOS legacy support and cannot be hotplugged, while Ethernet and audio fail to work entirely. This project fills that critical gap.
The xHCI98 driver replaces native Windows port and hub drivers to support USB 1.1, 2.0, and SuperSpeed devices. It also handles USB Attached SCSI storage via a secondary driver and connects Thunderbolt 3, USB4 docks, and NVMe enclosures through a third driver.
Testing and AI Assistance
Development and testing were primarily conducted on Intel hardware. The creator notes that bugs may occur even on identical hardware setups, such as the 2020 ThinkPad P14s Gen 1 featuring a Comet Lake xHCI configuration without EHCI.
The project utilized artificial intelligence assistance during creation, relying on different models for planning, coding, and adversarial code review.
Documentation accompanying the release details hardware verification procedures, installation methods, update instructions, and driver tuning guidelines for advanced users.
