I was able to fix this wifi issue in 2 laptops by following this procedure..No more wifi dropouts after doing this :
1. install the latest wifi driver + pro wiress software package from intel site
2. restart PC
3. Open device manager -> network adapter -> intel 6235 -> right click -> and uninstall driver (DO NOT uninstall pro wireless software from control panels -> programs)
4. Wait and Let windows automatically install the driver
5. Done.