possibly try removing in device manager if it is listed then scan for hardware changes may re-install itself. If its not listed in device manager and there are no yellow esclamation marks in Device manager then the computer doesnot see the attached. possibly hardware fail. Is the wireless componant listed under network adapters.
theres system filecheck Run box on the Start Menu and type in: sfc /scannow
this is the latest bios released for this machine make sure you are on this bios ESPRIMO M9400 Version: 1.06 use the iso image if it is not. to check goto system information and have a look. I think if "OS hanged" the event logs might have some info for when that happened and maybe point you in the correct direction.
No, system restore may remove some of earlier important wares and updates.Here there is
another thread about this problem,
so I hope to find a better solution.
thats a completely different machine and there is no solution on that thread.
I hope you are able to find a solution then without loosing your data. I recommend you back up your data on a monthly/weekly basis.