well i had my router on ground floor and everything was fine.i used to get 70% signals in my room(ROUTER WAS IN ANOTHER ROOM) and a couple of days ago i had to put router on 1st floor of some reasons.but now i get 30-40% signals and not even that some times my signals go to 80% and internet stops working and it keeps going 80% after little time intervals it comes back to 40 or 30 but again goes to 80 and internet won't work unitll i restart my network connection.and when i ping router's address the ping is so high 700ms something and sometimes it says timed out.i have seen people and i also when i newely bought this laptop it working fine when i placed router on roof.but now it does not .i tried reinstalling drivers and and updating my bios.nothing worked.my connection does not work on 40% or less signals.
It sounds like you have an inadequate wireless signal, which you can directly check with inDDISer, a freeware program that analyzes wireless signals available to your computer.
I would suggest adding a wireless access point (AP). If you cannot run a cable up to the dead zone, consider using a pair of powerline adapters to get the signal up to a router configured as an AP, did one this weekend for a relative and now they have a great signal throughout the house and in the back yard.
One other thing that can help is getting a an adapter with a better antenna, USB adapters are inexpensive and some have significant antennae. I would go with the AP first though.
Also, wireless signals change quality constantly depending on the interference from other 2.4GHz sources, microwaves, baby monitors, wireless speakers and headphones, wireless telephones, and other networks. So use inSSIDer to look for the least used channels between 1, 6, and 11 -- the three non-overlapping channels.