Just reinstalled Windows 7 Ultimate 32bit.
Now I see exclamtion marks for 2 USB adresses in Device Manager.
I have tested with new drivers
for the 2 USB addresses in focus, but
they are still having the issue.
I wonder if it is a defective USB sticker, as I recognized during a boot, thet
I got a message telling, that an USB overload had occured. After having unplugged
the sticker, I could boot again.
But the USB sticker is still in fuction