Wifi adapter and sound issues

Hi,

I originaly posted in the malware removal forum and was told my problem was software related:

A few months ago, after a windows 7 update, I kept getting a message about an known compatibity issue regarding a programme that came with my laptop (ACER 5750). I downloaded the hotfix and the message disapeared. I don't remember what the message said, but perhaps it is stored somewhere?

However, and I'm pretty sure the following issue appeared at the same time, the wifi adapter keeps turning itself off, as the wifi icon becomes grey with a red cross over it. When this happens, the sound becomes "buzzy" as well. Note that the laptop is set not to turn off wifi to save power.

Closing and reopening the laptop lid fixes that, as the wifi adapter would start again. However in the last few days, my laptop has started freezing too, and when I close it, most of the time i just get a black screen upon reopening, and a crash.

I would greatly appreciate any help on this, thanks.