My dad's machine had from memory that same drive. Its dead now and while dieing would cause lockup. Windows also thought it worked.
Try another drive.
Win98SE P3 800 Mhz 256 RAM ; Mitsumi CR4804te CD/RW
This has been a sturdy machine -- but a couple of lock ups and one blue screen happened. could only restart each with the longheld press on the power button.
Now I can not play or explore a CD, though the D drive is visible in My Computer, and device manager sees no problem, functioning normally.
have already dealt the *.vxd's that can cause conflicts.
I searched for newer drivers but there is nothing newer than version 3.0d as far as I can tell.
What else can i check?