*for all*This file, provided by Dell, is supposed to make USB work on Windows NT 4 systems. According to another forum, it worked, but since USB support in Windows NT 4 is not official, this should be treated with some caution. OldOs.org cannot be responsible for any damage done to your computer/data as a result of using this file.
Head over to http://files.oldos.org/files/updates/winntusb.exe and download the exe file (if you have networking in Nt 4 do it in the VM).
*extra steps if you did not download if you did not download in VM*
VMWare: Drag the file in on to desktop of VM.
Virtualbox & VirtualPC: Download ImgBurn from http://download.imgburn.com/SetupImgBurn_2.5.0.0.exe , install it, then create an iso that has the file added in, and then mount it in the VM. Open up the the CD ROM drive in VM.
*for all*
Double click the EXE File. Then just follow the on screen instructions.
VM stands for Virtual Machine