Laptop Wireless issue!?

I purchased my laptop - Sony Vaio E with windows 7 last year. It has Atheros AR9285 wireless adapter. My laptop keeps frequently disconnecting from the wireless internet connection (Comcast with Netgear Router running on b/g/n/mixed mode). It also indicates "Connection was reset" often while performing transactions. When diagnosed it says"problem with access point or wireless adapter". I have tried reinstalling the driver but no use. How do i solve this issue? Warranty period is over!