I heard that Windows 8 have problems with Wifi handling. Check the latest avliable frimware for v7 and try to use that. Make sure to use he latest drivers for your network adapter too...(note: every driver have a different version for Win8.1 and Win8 so be sure to install the right one). You don't meantioned eralier so just for case, did you enabled auto reconnection for that network?

Link for the latest frimware for your router: Link

If these simple solutions will not resolve your problem pls write down exactly your laptop's model number and Windows version number that you are using (8.1 or 8.0).
Sry for bad English... :)