I have been having this problem with windows 7. A lot of the time windows 7 shuts off my wireless belkin adapter for my wifi. I check in power settings and under the wireless adapter settings I have choose a setting of maximum performance. But if I leave the computer for a while it seems to shut it off which is really anoying when I want to leave stuff downloading overnight. Any Ideas?
More aboutwin7 shutting wireless adapter
Set up an appropriate power plan Control panel Power Options Advanced