You should first be sure the USB ports are installed/functioning, I doubt they are 
with this error. Right-click 'My Computer', select 'Properties' and then 'Device 
Manager'. The installed USB ports should list under 'Universal Serial Bus controllers' 
at the bottom of the device listings. If it's not there, it may be necessary to enable 
it within the BIOS setup.

If necessary, read this article to explain one possible solution, then try extracting 
each file with System File Checker. It isn't necessary to rename the files with this 
procedure. This solution only applies if the devices are properly listed in 'Device 
Manager'.

The NTKERN.VxD 
device loaders for this device could not load the device driver (Code 2).

Insert your Win98 CD rom in the drive. Select Start/Run, type SFC 
in the 'Open' box and press enter.

When System File Checker opens, select 'Extract One File from installation 
disk'.

Enter UHCD.SYS in the search box and press enter.

When the 'Extract File' window opens, the 'Restore From' box should 
be set to your CDROM drive letter as X:\Win98 (where 'X' is the assigned CDROM drive 
letter). The 'Save file in:' box should read C:\Windows\System32\Drivers. 

Now select 'OK' and follow the prompts.

Now repeat the above procedure for these two files:

USBHUB.SYS

USBD.SYS