How to turn a smartphone's WiFi into a router for a computer?

In Mobile phones, there are inbuilt options to provide WIFI hot spots for other mobiles but for your Pc to access Hotspot of your Mobile. You can try this option. ( It's just a try can't give 100% assurance that it can work but its worth a try, if its needed badly.)

Download Android Wifi tether from Play store, this will help you connect your mobile with LAN network. Works only for few mobiles and look out for APP in the play store as it is just a work of a developer and hasn't achieved much limelight. so should search in play store.

Download the respective drivers in PC and configure your LAN connection with your PC and mobile and check for connection.

Hope this helps.

IN phone:
Settings>tethering &portable hotspot>1.portable wifi hotspot settings>configure wifi hotspot> 2.portable wifi hotspot(on/off)
Then set 1. user id(SSID) :xxx..
2.security :WPA2PSK
3.password :yyyy..
and save it then turn on portable wifi hotspot.
IN pc:
If your pc possess wifi drivers,then turn wifi on and select the SSID that has been used in the smart phone and enter the password similar to the password you kept in your mobile for that particular SSID.

Almost all the smartphones coming out into the market these days are capable of working as a portable hotspot. But it involves usage of costly data plans. The settings to activate the WiFi hotspot mode differs across devices from different manufacturers.
On a typical Android phone, you will need to follow these steps.

1. Go into your Settings.

2. Locate the Tethering and Portable Hotspot option. It should be available under Networks tab.

3. Set up your hotspot using your own password. The steps involved are self explanatory.

4. Turn on the Hotspot mode by swiping the slider.

The exact position of the settings may differ depending on the customisation used by your device manufacturer.

Please note that there are many apps available on Play Store to be able use the Hotspot feature without having to do much on your part. Your smartphone should be able to tether its 3G or 4G connectivity with devices within a range of around 5 meters.

I know how to tether internet to PC. May be you did not understood my question. As we can tether our smartphones camera to PC via USB as a web camera exactly I want to tether my smartphones WiFi so that available list of networks(hotspots) I can see in my PC.