WinME sees HW changes - but I made no changes

Here's what happened - can anyone explain why?
My PC had been working fine for a long time and I hadn't installed or
connected any new hardware, nor installed any new software. But I needed to
take out the MOBO to do some work on the PC case. So I removed the cards
and the MOBO and did the necessary case mod, then I put everything back in
just like it was when I started. All the cards in the same slots, HDs
configured the same as when I started.

When I switched the PC on it booted fine but Windows (WinME) said it found
the following new hardware:
Onboard IDE Controllers 1 & 2
also my HP Deskjet 400 printer

Over the years I've seen this kind of thing happen on other PCs once in a
while and it has always puzzled me. One time I pulled out a PCI card while
the power supple was still plugged in. It didn't damage the machine
(luckily) but it totally scrambled the configuration settings and Windows
detected every device in the box as though they had just been added - but
eventually it straightened everything out. I wasn't puzzled about that
one - I'm sure that problem was the result of pulling the card out with the
power supply plugged in.

In the present case THERE WAS ONE THIND I DID that could have caused a
problem. I plugged my speakers (powered speakers) into the sound card while
the speakers were powered on. I did that just before switching the PC on
after the rebuild. Maybe it caused a voltage to the MOBO that affected the
PCI configuration data stored on the board.

The MOBO in this case is ASUS A7V266.

Does anyone here have an idea what caused Windows to detect the IDE
controllers and printers as newly installed devices?

TIA. Bill S.

 

Although he hardware is the same the IRQ and resources will be redistributed
and thus detects it as new hardware.