Why in laptop Wi-Fi is not showed?

If you can't see any wireless networks, probably wireless is not opened. You need to press wireless button. This button is shown with a wireless sign.

Connect to your Router with an Ethernet Cable. Http://www.bing.com/images/search?q=ethe…
Then go to Lenovo Support and get your WLAN driver.

You can right click the Wi-Fi signal and hit troubleshoot.

Look in device manager under network adapters and see if the Wi-Fi adapter is listed.

You may need to download the latest drivers from Lenovo's site, however, with the extreme lack of information you have provided - "my computer's broke, fix it" - it is impossible to say. What did you do to it before this started? What exactly is displayed on the screen when you try to connect? Have you tried connecting an Ethernet cable - always the preferred method over Wi-Fi just isn't reliable enough.