You can use your Android phone as a wireless modem to surf internet on your PC, you can do this without rooting your Android phone. Here is a really simple and easiest way to turn your android mobile as a wireless modem for your PC. For this you require a free android app, an android phone and a PC.
PdaNet android app does not require root access of your phone firmware. It is just a regular free Android app which works smoothly on android phones. PdaNet allows your computer to go online through the Android phone’s Internet connection. Supports USB/Bluetooth DUN. It does not require a tether plan or rooting. Supports Mac and PC. Easy and fast! Your phone can either connect to 3G data or WiFi, even through VPN and PdaNet will share the connection with your computer.
Step 1. Download the PDAnet for your computer from here and install it on your PC.
Step 2. After the installation, now download PDAnet for your Android phone from here and install it on your Android Device.
Step 3. After the installation on your Phone, run the app and tap Enable USB Tether.
Step 4. Now connect your Android phone using your USB Cable and it will connect to the Internet Automatically, Or click on the PdaNet tray icon and your computer will go online instantly.
PdaNet also includes an additional SMS Agent app allowing you to send or receive SMS from PC.