Acer extensa 5420 help!

I have an Acer Extensa on display at a radio shack store, and after an eveing of use by an associate, the keyboard and mouse are not responding. I currently have a wireless mouse and a usb keyboard connected so I can use it, but we desperately need some help. i have the same stupied problem,,,my computer keyboard and mouse isnt working anymore,,i had to buy a wireless mouse,,,im comfused and in need of help,,,can anyone out the assist me in this?,,

tks..osa....