using win7 pro on asus laptop 's' key is not working how to fix it

Again I'm typing this on a sticky note app.......I use Firefox and it's across the board for the "S" key...I go offline and go to a document or whatever and the "S" works....I go back online and it doesn't work

Plug in a USB keyboard to see if the problem goes away. If so try cleaning the keyboard. To be extra safe, power down, unplug battery and power adapter, hold power button to release residual power. Now turn the laptop upside down, hold firmly while you rake your fingers across all rows of keys, back and forth. If this dislodges a lot of crumbs and other debris then that could be your problem. I sometimes use a plastic vacuum attachment to get the stubborn stuff out.

You can't be careless or you could drop the laptop or damage it. Use a firm grip and controlled motions, slow and deliberate.

I have been able to salvage any laptop keyboards with these problems before by cleaning them up like this, replacing keys if needed. But you may need to replace the keyboard if you don't want to use a USB. Remember you can also plug in a monitor to use the laptop like a desktop if you are so inclined. I'm doing that now at home with my i5 travel laptop because I like the SSD drive's speed so much.