Computer motherboard is a QDI SUPERB 4V-ALX motherboard, with a Pentium 4.
For some strange reasons, after I re-assembled the computer and re-installed Windows 98 SE, the computer USB stopped working at all!

I tried using a USB Pen drive 4Gb, which works perfectly. And worked in this system too.

I tried the front USB, the back USB and the expansion USB (which uses the internal USB ports) and it doesn't work at all. The pen drive led stays on without a single blink on all of these ports. All of these worked before!

I tried looking in the bios and nothing works.

In Windows it doesn't even pop up the New Hardware Found wizard, and the device manager looked fine.
So thinking that it was Windows 98 SE the problem, I installed ME and it still doesn't work!! (I had ME installed before and it worked perfectly!).

I don't have any clue, I f*****g hate this dumb problem!
It just magically appeared out of nowhere! It was perfectly working before and I reassembled it perfecly!!
Heck, it even looks like someone did that on purpose, there is no explanation!! 😠 😠