This Pentium 133 MHz PC (with ASUS P55T2P4 motherboard) had been sitting under my table for years. It is a 10 year old PC. I decided to put all my old obselete hardware together into this PC to see whether it can be powered up or not. And to my surprise, it is actually still working.
This PC still uses the good old keyboard interface. It is expecting mouse with serial interface. That is how old it is. It is too slow to run Windows Millennium. Thus, I installed Windows 98 onto it. I added a USB card in it so that it can connect to my USB mouse and my USB network adaptor. Everything works just fine.
The only problem is, the CMOS battery is bad. But it is an onboard BenchMarQ chip that cannot be easily replaced.