|Windows ME only has built-in support for USB 1.1. A USB device that is designed to work with *both* USB 1.1 and USB 2.0 will function, though only at USB 1.1 speeds, but ONLY if it's designed to work with BOTH.|
Therefore check whether your USB device is designed to work with USB 1.1 (i.e. look on the box), because if the box says it is designed for USB 2.0 only then it won't work in WinME, at least not on your motherboard's USB ports.
Yes, Windows ME *does* have built-in USB drivers. But they are USB 1.1 drivers! You can't run a USB 2.0 device on the built-in drivers. The device must be *specifically* stated to be for USB 1.1 (whether or not it is also for USB 2.0), or it won't work in WinME.
To use a USB 2.0 device in Win ME you have to buy an add-in USB 2.0 PCI expansion card. It MUST be one that comes with a USB 2.0 driver file for WinME (called a USB "mass storage driver").
It is prudent to buy a PCI card that (a) has an NEC chipset, as that chipset has the widest compatibility with older motherboards; and (b) that comes with a driver file for USB 2.0; and (c) that says on the box that it's compatible with either Windows 98 or Windows ME.
Try the website of the Card's manufacturer. Download such a driver file to your Desktop; then install the driver file, using its setup program (they almost always come with setup software included).
If the Card manufacturer hasn't provided a driver, you can try the following sites for any available so-called "universal" USB 2.0 drivers for Windows 98/ME (but not all PCI Cards will work with these generic drivers):