My computer (Acer) has 4 USB port on the front panel and a multiple card reader. Previously under the "My Computer" icon, all the card slots were always listed, now they have gone.

When I plug in a card, nothing happens, while before a window opened asking me what action I wanted.

Similarly, the four USB ports also seem to be inactive. When I plug in a device, no sound and no action and nothing is recognized.

Restarting the computer does not help.

Can some tell me what I did wrong and how I can repair that?

If your comp still has Warranty, I would suggest you to bring the comp to the Head Service Center from ACER at Rama 3 Road.

I had some ports go missing once.

Had to reset the CMOS to fix it.

First, check in "device manager" if all USB stuff is enabled. On my PC, I can not see these USB ports under "My Computer", but they work fine

First, check in "device manager" if all USB stuff is enabled. On my PC, I can not see these USB ports under "My Computer", but they work fine

In My Computer you can't see the USB ports anyway byt the connected device if and as long as they connected.

Disconnect all USB devices. In Windows Device Manager, uninstall the USB controllers. Reboot, see if Windows reinstalls your USB ports.

Thanks everybody for the help.

I thought I might explain how I solved the problem:

At startup I push the <Delete> key to enter the BIOS Setup. There I disabled the USB Chipset and restarted the computer. Then I shut down again and at startup go again in the BIOS Setup, re-enable the USB Chipset and ... voilà! All the USB ports and all the card reader slots were back.

One word of caution, though: My keyboard and mouse were attached to a USB port, so they did not respond anymore after disabling the chipset in the BIOS Setup. OK OK, I know ... I am a lousy computer user. I found an old keyboard and mouse which I attached to the purple and green connectors just for the 2nd. startup. After enabling the USB chipset again, I switched back to the previous mouse / keyboard and now everything is working fine.

Thanks again, everybody.