acer Laptop running windows 7 losing wireless connection and freezing

Evening guys. i have the following problem :

Acer aspire 5750 laptop ( about 9 months old )
wireless internet with 'excellent' signal strength on internet
windows 7 home premium



the problem i'm getting is that constantly now the laptop losing its internet connection (goes to limited connectivity) or cannot connect then when i try troubleshooting/diagnosing/open the network center as soon as i run the troubleshooting etc the laptop freezes then the only way it will work again is to turn it off and back on, i would then get an internet connection again, sometimes for half an hour but often no more than five minutes.

I'm pretty sure the wireless Internet is not the issue as the fault occurs exactly the same at

My house
Girlfriends house
and has also happened when using a friends wireless at his place
so the same internet connection fault occurs at three separate connections which leads me to believe its the laptop playing up .

any ideas, help or checks i could do would be great .
thanks in advance

Some common issues I have found to resolve similar type issues are:

1. Update network driver
2. Delete network profiles and remake them
3. run a "netsh winsock reset" from command prompt
4. Update Bios, may be a PCI communication error?
5. Replace wifi card (under warranty?)
6. Run a virus scan, somthing like Offline defender, good sucess with this, or Kaspersky rescue disc.