Wi-fi problems. Please. G700?

I have a Lenovo G700, with 802.11b/g/n Wi-Fi connectivity.
My rooms upstairs and I use an extension to get Wi-Fi though I'm quite close to the lan downstairs considering.

It gives the illusion of full bars but in reality, if I were to watch a youtube video the auto-resolution is 144p D:
What can I do to fix this? Is there a way to upgrade a computer part or get a new extension or do I have to live with it: l

Many thanks
C

ps. Is there also something I could change so my computer doesn't freeze when I try to screencast?

!Cherry-Blossom!

If it is showing full tower means surely it ll work. Tat won't be an illusion, first you check your internet speed in some speed checking site. Then you can know your speed. If it is illusion use some good extension cable with noise reducer. Tat ll be good for your problem

sabari