To trace Unknown Hardware, I first see what optional Windows Updates delivers because lately almost all missing drivers are provided in the first round.

Any still missing, go to the Support Downloads webpage for your Acer here to see what isn't installed. Looking over the list it's likely the card reader or modem.

If you don't find the missing driver on Acer webpage for the model then use this method to trace the Hardware ID which will give you the make and then the model to google for a Win7 or Vista driver: Hardware Identification